Disassembly Headphone Sennheiser RS 120

I repaired some similar Sennheiser headphones recently. If you press the ear pads down towards the centre you will see a series of around a dozen plastic tabs which retain a piece of plastic to which the ear pads are attached. Prise this plastic out from the tabs with a small screwdriver or prying tool and the ear pads will come off.

You will then see an oval of foam surrounding the driver. Under this are 4 screws that you can locate by feel. Remove them and the driver comes out. Replacing it, the fork has to be in the correct position before it will sit flush.