I have checked the top of the system on a Roca dual flush toilet and cannot decide how you remove the lid there is no doubt a simple method, is it push one of the centre buttons down and reomove the outside case .

Terry W, August 2009

If it is a two-buttons on top of the lid, try this:
- shut off the water supply into the cistern;
- press one of the flush buttons so you can prize the other with a screwdriver (not too much force) or just your fingers, then the first one.
- there should be a screw (probably plastic) beneath the two buttons.
Hope this helps

Gramps, August 2009