Thanks for the advice, hj. I am not a plumber so please excuse dumb questions. The liner was installed with a drain "stopper" that is pulled up to open and pushed down to close the drain. It was no problem to remove that. It screws in to a cross piece lower down in the drain opening. I think what you are suggesting is to remove the flanged assembly into which the stopper mechanism fits. I don't know if that is somehow screwed into the original tub drain opening or more of a friction fit, possibly with an o-ring or similar seal. Or could the drain assembly have been attached to the liner with a large nut on the bottom of the liner before the liner was dropped into the tub? Bottom line, I don't know for sure what my next step should be and am not yet to the point where I don't care if I rip up the liner.