The single lever mixer kitchen sink tap has decided to stop working. Operating the lever it feels lumpy as though it is not turning the internal workings. I believe I have found a replacement one at £60 which seems expensive for what it is but looking at my sink and tap can see no way of getting at it. It seems to me that the sink and tap were fitted to the worktop before it was fitted on top of the kitchen units. I can just get my hand under the sink and up the back and feel the pipe connectors and that's about it. Anybody any idea how the tap body is fitted to the work top eg screws somewhere or a bloody big nut, and would it be easier to cut a section out of the wardrobe wall to access behind the sink.