diff --git a/src/model/user/member.rs b/src/model/user/member.rs
index 9161ac6..faebd87 100644
--- a/src/model/user/member.rs
+++ b/src/model/user/member.rs
@@ -1,6 +1,7 @@
 use super::ScheckbuchUser;
 use crate::model::{
     logbook::{Logbook, LogbookWithBoatAndRowers},
+    role::Role,
     user::User,
 };
 use serde::{Deserialize, Serialize};
diff --git a/src/model/user/mod.rs b/src/model/user/mod.rs
index 8ca32b8..ba89924 100644
--- a/src/model/user/mod.rs
+++ b/src/model/user/mod.rs
@@ -35,7 +35,7 @@ use scheckbuch::ScheckbuchUser;
 mod basic;
 mod fee;
 pub(crate) mod member;
-mod scheckbuch;
+pub(crate) mod scheckbuch;
 
 #[derive(FromRow, Serialize, Deserialize, Clone, Debug, Eq, Hash, PartialEq)]
 pub struct User {
diff --git a/src/model/user/scheckbuch.rs b/src/model/user/scheckbuch.rs
index 2521eef..9a66521 100644
--- a/src/model/user/scheckbuch.rs
+++ b/src/model/user/scheckbuch.rs
@@ -1,10 +1,15 @@
-use super::User;
+use super::member::Member;
+use super::{ManageUserUser, User};
+use crate::model::role::Role;
 use crate::model::user::LoginError;
+use crate::tera::admin::user::ScheckToRegularForm;
 use crate::{
     model::{mail::Mail, notification::Notification},
     special_user, SCHECKBUCH,
 };
+use chrono::NaiveDate;
 use rocket::async_trait;
+use rocket::fs::TempFile;
 use rocket::http::Status;
 use rocket::request;
 use rocket::request::FromRequest;
@@ -16,10 +21,39 @@ use std::ops::Deref;
 special_user!(ScheckbuchUser, +"scheckbuch");
 
 impl ScheckbuchUser {
+    pub(crate) async fn convert_to_regular_user(
+        self,
+        db: &SqlitePool,
+        changed_by: &ManageUserUser,
+        member_since: &NaiveDate,
+        birthdate: &NaiveDate,
+        phone: &str,
+        address: &str,
+        membership_pdf: &TempFile<'_>,
+    ) -> Result<(), String> {
+        // Set data
+        self.user.update_birthdate(db, changed_by, birthdate).await;
+        self.user
+            .update_member_since(db, changed_by, member_since)
+            .await;
+        self.user.update_phone(db, changed_by, phone).await?;
+        self.user.update_address(db, changed_by, address).await?;
+        self.user.update_address(db, changed_by, address).await?;
+        self.user
+            .add_membership_pdf(db, changed_by, membership_pdf)
+            .await?;
+
+        // Change roles
+        let regular = Role::find_by_name(db, "Donau Linz").await.unwrap();
+        let scheckbook = Role::find_by_name(db, "scheckbuch").await.unwrap();
+        self.user.remove_role(db, changed_by, &scheckbook).await?;
+        self.user.add_role(db, changed_by, &regular).await?;
+
+        // Notify
+        todo!() // Continue here
+    }
+
     //async fn from(user: User, db: &SqlitePool, mail: &str, smtp_pw: &str) -> Result<(), String> {
-    //    // TODO: see when/how to invoke this function (explicit `Neue Person hinzufügen` button?
-    //    // Button to transition existing users to scheckbuch? Automatically called when
-    //    // `scheckbuch` is newly selected as role?
     //    if user.has_role(db, "scheckbuch").await {
     //        return Err("User is already a scheckbuch".into());
     //    }
diff --git a/src/tera/admin/user.rs b/src/tera/admin/user.rs
index 42b40f0..6c89e0e 100644
--- a/src/tera/admin/user.rs
+++ b/src/tera/admin/user.rs
@@ -7,8 +7,9 @@ use crate::{
         logbook::Logbook,
         role::Role,
         user::{
-            member::Member, AdminUser, AllowedToEditPaymentStatusUser, ManageUserUser, User,
-            UserWithDetails, UserWithMembershipPdf, UserWithRolesAndMembershipPdf, VorstandUser,
+            member::Member, scheckbuch::ScheckbuchUser, AdminUser, AllowedToEditPaymentStatusUser,
+            ManageUserUser, User, UserWithDetails, UserWithMembershipPdf,
+            UserWithRolesAndMembershipPdf, VorstandUser,
         },
     },
     tera::Config,
@@ -813,6 +814,68 @@ struct UserAddScheckbuchForm<'r> {
 //    Flash::success(Redirect::to("/admin/schnupper"), format!("Scheckbuch erfolgreich erstellt. Eine E-Mail in der alles erklärt wird, wurde an {} verschickt.", user.mail.unwrap()))
 //}
 
+#[derive(FromForm, Debug)]
+pub struct ScheckToRegularForm<'a> {
+    member_since: String,
+    birthdate: String,
+    phone: String,
+    address: String,
+    membership_pdf: TempFile<'a>,
+}
+
+#[post("/user/<id>/scheckbook-to-regular", data = "<data>")]
+async fn scheckbook_to_regular(
+    db: &State<SqlitePool>,
+    data: Form<ScheckToRegularForm<'_>>,
+    admin: ManageUserUser,
+    id: i32,
+) -> Flash<Redirect> {
+    let Some(user) = User::find_by_id(db, id).await else {
+        return Flash::error(
+            Redirect::to("/admin/user"),
+            format!("User with ID {} does not exist!", id),
+        );
+    };
+    let Ok(birthdate) = NaiveDate::parse_from_str(&data.birthdate, "%Y-%m-%d") else {
+        return Flash::error(
+            Redirect::to("/admin/user/{id}"),
+            format!("Datum {} ist nicht im YYYY-MM-DD Format", &data.birthdate),
+        );
+    };
+    let Ok(member_since) = NaiveDate::parse_from_str(&data.member_since, "%Y-%m-%d") else {
+        return Flash::error(
+            Redirect::to("/admin/user/{id}"),
+            format!("Datum {} ist nicht im YYYY-MM-DD Format", &data.birthdate),
+        );
+    };
+
+    let Some(user) = ScheckbuchUser::new(db, &user).await else {
+        return Flash::error(
+            Redirect::to("/admin/user/{id}"),
+            "User ist kein Scheckbuchuser",
+        );
+    };
+
+    match user
+        .convert_to_regular_user(
+            db,
+            &admin,
+            &member_since,
+            &birthdate,
+            &data.phone,
+            &data.address,
+            &data.membership_pdf,
+        )
+        .await
+    {
+        Ok(_) => Flash::success(
+            Redirect::to(format!("/admin/user/{}", id)),
+            "Mitgliedstyp umgewandelt und Infos versendet",
+        ),
+        Err(e) => Flash::error(Redirect::to(format!("/admin/user/{}", id)), e),
+    }
+}
+
 pub fn routes() -> Vec<Route> {
     routes![
         index,
@@ -840,5 +903,7 @@ pub fn routes() -> Vec<Route> {
         add_membership_pdf,
         add_role,
         remove_role,
+        //
+        scheckbook_to_regular,
     ]
 }
diff --git a/templates/admin/user/view.html.tera b/templates/admin/user/view.html.tera
index 9a32444..64b2c4b 100644
--- a/templates/admin/user/view.html.tera
+++ b/templates/admin/user/view.html.tera
@@ -209,7 +209,7 @@
                             ⚠️ Aktuell gibt's keine Beitrittserklärung 😢
                             {% if allowed_to_edit %}
                                 Das kannst du hier ändern ⤵️
-                                <form action="/admin/user/{{ user.id }}/add-membership-pdf" method="post">
+                                <form action="/admin/user/{{ user.id }}/add-membership-pdf" method="post" enctype="multipart/form-data">
                                     <fieldset>
                                         {{ macros::input(label='Neue Beitrittserklärung hochladen', name='membership_pdf', type="file", accept='application/pdf') }}
                                         <input value="Hochladen" type="submit" class="btn btn-primary ml-1" />
@@ -252,6 +252,19 @@
                                 {{ log::show_old(log=log, state="completed", only_ones=false, index=loop.index, allowed_to_edit=false) }}
                             {% endfor %}
                         </details>
+                        <details>
+                        <summary>Zu reguläres Vereinsmitglied umwandeln</summary>
+                        <form action="/admin/user/{{ user.id }}/scheckbook-to-regular" method="post" enctype="multipart/form-data">
+                              {{ macros::input(label='Mitglied seit', name='member_since', type="date", value=now() | date()) }}
+                              {{ macros::input(label='Geburtsdatum', name='birthdate', type="date", value=user.birthdate) }}
+                              {{ macros::input(label='Telefonnummer', name='phone', type="text", value=user.phone) }}
+                              {{ macros::input(label='Adresse', name='address', type="text", value=user.address) }}
+                              {{ macros::input(label='Beitrittserklärung', name='membership_pdf', type="file", accept='application/pdf') }}
+                              <input value="Als neues, reguläres Mitglied anlegen" type="submit" class="btn btn-primary ml-1" />
+                        </form>
+                        </details>
+
+
                     {% elif "Regular" in member %}
                         ist ein reguläres Vereinsmitglied.
                     {% elif "Foerdernd" in member %}