Hi, still very new to this forum - this is my 2nd posting. Please help if you can. I am replacing round head taps with lever taps (am recently retired and have too much time on my hands!) and have fitted a new hot tap no probs. The cold tap has slightly different pipework - a white plastic tubular insert in the metal feed pipe and 2 plastic nuts one at top (yellow) and one (white) at bottom, and a 3rd plastic nut (yellow) underneath the lowest white plastic nut. I don't know the sizes of them as my plumbers wrench (1 inch/25mm and 1.25 inch/30mm approx.) does not fit (but fitted the metal nut on the hot tap). I replaced the cold tap but after tightening up and when centring the tap with my hand I caused it to leak - so tightened it up again using a plumber's claw wrench. I am working from top down not from underneath as cannot get leverage. The top plastic nut sheared whilst tightening so I have tried removing the bottom nuts (one white and one yellow) but they just swivel around in unison. Could anyone suggest the best way of tackling this, so that I can fit the new tap ? See photos attached. Thanks.