I am replacing my shower basin but am having a hard Time removing the brass ring. The basin is flush with the ring, then there is about a 1/2" space then the drain pipe. The space in between the ring and the pipe looks like it is apart of the ring, I'm not really sure. It looks like there should be a tool that expands and adds pressure to the ring and then you can just twist off, hopefully I'm not dreaming.

Pictures always help.:D

What material is the shower raiser made of? If it's plastic then the drain's glued in. If it's cast iron then you have a lead and oakum joint. Cheers, Tom