Hi, I have a Twyford toilet that has been running all weekend. I would like to fix it myself but I 'm unable to lift up the lid on the tank. I don't want to force it too much in case I break something. There are no screws, it seems to be fitted through the overflow tube. The flusher is in the middle of the lid, it's a dual flusher that you press down. Has anybody got this type of toilet? Please can somebody tell me how to remove the freaking thing?