I am trying to replace the hardware in a bathroom sink built by Shea homes in 2001. I disconnected the piping below the sink but the waste seat (the thing the stopper goes into on the top side of the bowl) appears to be fused to the metal attachment on the underside of the bowl. I had hoped that the top part was screwed into the bottom part but it seems as if they are truly fused together or somehow manufactured that way. In any case I can't pass the due through the hole in the bowl because it doesn't fit. As a result I would either need to remove and replace the entire bowl or unscrew the top piece from the bottom piece if so advised by this forum. Can anyone help with this one? Thanks in advance.

Steve

They screw together. Take out the stopper and wedge a pair of pliers into the top. Now have someone hold the bottom tail piece and unscrew it. Sometimes you need to cut the parts off to get them out.