Can someone please tell me how to get the lid off a low-flush ROCA toilet cistern? The toilet itself is brand new and I want to paint down behind the cistern. I thought that cistern lids merely lifted off, however this one appears not to. It is one of the low-flush kind with two chrome push buttons on the top of it (as opposed to having a handle). I’ve tried sliding the lid off, but that doesn’t appear to work either, and there doesn’t appear to be any screws / bolts holding the lid down. Any help would be gratefully received.