UK Car Repair: Steering wheel on late MGB, aftermarket wheels, horn button

Question
have a 77 MGB with wooden steering wheel (either after-market or an earlier model MG) with a horn button in center. How do I remove the button without breaking it? I've tried pushing it in and turning it but no luck.

Answer
The aftermarket wheels have a trim cover which will come off with a gentle pull, the screws can then be seen. Original wheels can be Bayonet fitting, this has to be pushed in then rotated to release it or, some have small screw/s going in from the side of the column hub, undo these and it will come off.