Shower drain caulk failure
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Just had a shower installed but the PVC no-caulk drain is leaking into the basement. The plumber said everything was was tested and worked fine, and now left for vacation. It's leaking where he siliconed it to the fiberglass shower base (and then down between the threads and the big plastic nut underneath). I have no qualms about replacing it myself (in-laws are on the way) but I'm worried about damaging the shower base trying to remove the one that's already caulked onto it. Is this do-able, or will I damage the base trying to remove it? Thanks in advance.
(my apologies for having previously posted this question under construction topics, I'm new here and didn't realize there was a specific plumbing category)