To delete a user, the user must be open for editing.
Open User Management by clicking on the User icon in the menu.
In the row of the user that you want to delete, click on the "Edit" icon
In the now opened Edit view, open the context menu of this view by clicking on the "User" label.
Select the "Delete" command.
Click on "Delete" in the dialog window that opens to confirm the deletion.
If you have have selected the incorrect user, you can still cancel the deletion by clicking on "Cancel".
The user that is currently logged in cannot delete themselves!