I have a leak from my shower drain that appears to be going around the gasket and over the 2" pvc pipe. This is a stand up shower with a Sioux Chief brass drain. I removed the drain grill (snap in) and the locking ring. There is a gasket that sits over the pvc pipe that seems weird, maybe squished in on one side and I believe if I replace that gasket, it should solve the leak. I am guessing and am very 'green' at plumbing fixes but am willing to try. What is the best way to remove and replace that gasket? I have tried to grab it with a needle nose pliers, flat edged screwdriver, etc.. but am being cautious as I don't want to damage the PVC pipe. Any suggestions? Thank you!