diff --git a/src/notes/notes.service.ts b/src/notes/notes.service.ts
index de6aa31de..f55337f1e 100644
--- a/src/notes/notes.service.ts
+++ b/src/notes/notes.service.ts
@@ -14,6 +14,7 @@ import {
   NotInDBError,
   PermissionsUpdateInconsistentError,
 } from '../errors/errors';
+import { Group } from '../groups/group.entity';
 import { GroupsService } from '../groups/groups.service';
 import { HistoryEntry } from '../history/history-entry.entity';
 import { ConsoleLoggerService } from '../logger/console-logger.service';
@@ -335,6 +336,117 @@ export class NotesService {
     return await this.noteRepository.save(note);
   }
 
+  /**
+   * @async
+   * Set permission for a specific user on a note.
+   * @param {Note} note - the note
+   * @param {User} permissionUser - the user for which the permission should be set
+   * @param {boolean} canEdit - specifies if the user can edit the note
+   * @return {Note} the note with the new permission
+   */
+  async setUserPermission(
+    note: Note,
+    permissionUser: User,
+    canEdit: boolean,
+  ): Promise<Note> {
+    const permissions = await note.userPermissions;
+    const permission = permissions.find(
+      (value: NoteUserPermission, index: number) => {
+        if (value.user.id == permissionUser.id) {
+          if (value.canEdit != canEdit) {
+            value.canEdit = canEdit;
+            permissions[index] = value;
+          }
+          return true;
+        }
+      },
+    );
+    if (permission == undefined) {
+      const noteUserPermission = NoteUserPermission.create(
+        permissionUser,
+        note,
+        canEdit,
+      );
+      (await note.userPermissions).push(noteUserPermission);
+    }
+    return await this.noteRepository.save(note);
+  }
+
+  /**
+   * @async
+   * Remove permission for a specific user on a note.
+   * @param {Note} note - the note
+   * @param {User} permissionUser - the user for which the permission should be set
+   * @return {Note} the note with the new permission
+   */
+  async removeUserPermission(note: Note, permissionUser: User): Promise<Note> {
+    const permissions = await note.userPermissions;
+    const permissionsFiltered = permissions.filter(
+      (value: NoteUserPermission) => {
+        return value.user.id != permissionUser.id;
+      },
+    );
+    note.userPermissions = Promise.resolve(permissionsFiltered);
+    return await this.noteRepository.save(note);
+  }
+
+  /**
+   * @async
+   * Set permission for a specific group on a note.
+   * @param {Note} note - the note
+   * @param {Group} permissionGroup - the group for which the permission should be set
+   * @param {boolean} canEdit - specifies if the group can edit the note
+   * @return {Note} the note with the new permission
+   */
+  async setGroupPermission(
+    note: Note,
+    permissionGroup: Group,
+    canEdit: boolean,
+  ): Promise<Note> {
+    const permissions = await note.groupPermissions;
+    const permission = permissions.find(
+      (value: NoteGroupPermission, index: number) => {
+        if (value.group.id == permissionGroup.id) {
+          if (value.canEdit != canEdit) {
+            value.canEdit = canEdit;
+            permissions[index] = value;
+          }
+          return true;
+        }
+      },
+    );
+    if (permission == undefined) {
+      const noteGroupPermission = NoteGroupPermission.create(
+        permissionGroup,
+        note,
+        canEdit,
+      );
+      (await note.groupPermissions).push(noteGroupPermission);
+    }
+    return await this.noteRepository.save(note);
+  }
+
+  /**
+   * @async
+   * Remove permission for a specific group on a note.
+   * @param {Note} note - the note
+   * @param {Group} permissionGroup - the group for which the permission should be set
+   * @return {Note} the note with the new permission
+   */
+  async removeGroupPermission(
+    note: Note,
+    permissionGroup: Group,
+  ): Promise<Note> {
+    const permissions = await note.groupPermissions;
+    const permissionsFiltered = permissions.filter(
+      (value: NoteGroupPermission) => {
+        return value.group.id != permissionGroup.id;
+      },
+    );
+    note.groupPermissions = Promise.resolve(permissionsFiltered);
+    return await this.noteRepository.save(note);
+  }
+
   /**
    * @async
    * Calculate the updateUser (for the NoteDto) for a Note.
@@ -417,6 +529,18 @@ export class NotesService {
     };
   }
 
+  /**
+   * @async
+   * Updates the owner of a note.
+   * @param {Note} note - the note to use
+   * @param {User} owner - the new owner
+   * @return {Note} the updated note
+   */
+  async changeOwner(note: Note, owner: User): Promise<Note> {
+    note.owner = Promise.resolve(owner);
+    return await this.noteRepository.save(note);
+  }
+
   /**
    * @async
    * Build NoteDto from a note.