Thanks for replies.
I managed to detach the plate by moving a credit card between the plate and the monitor. It is a bit tricky to get it in, had to help with my fingernails. After it was between I slowly shoved it through. It needs some patient and force. The monitor had no marks 🙂 So using a plastic card works good.
@pi: thanks for the idea for the logo. My next monitor has it right in the middle…