Read-only file: Cannot save it with VBA code

[chrisignm]

Hi, what I'm trying to do:

I have a read-only file. I want to save the file AFTER I did some changes to it.

I got a VBA code, but it only works if the file is 100% the same (no changes were made):

Sub SaveAfterUpdate()
If ActiveWorkbook.ReadOnly Then
With ActiveWorkbook
        SetAttr .FullName, vbNormal
        .ChangeFileAccess Mode:=xlReadWrite, WritePassword:="admin"
 
        Application.DisplayAlerts = False
        .Save
        Application.DisplayAlerts = True
        .ChangeFileAccess Mode:=xlReadOnly, WritePassword:="admin"
    End With
Else
With ActiveWorkbook
Application.DisplayAlerts = False
        .Save
Application.DisplayAlerts = True
.ChangeFileAccess Mode:=xlReadOnly, WritePassword:="admin"
End With
End If
End Sub

Could somebody please tell me how to save the read-only file also when I made changes? (and save as read-only again!)

Reason: Part of an automatized update routine

edit: The problem is basically that I can't remove read-only If I changed something within the file.

Thanks alot