I'm currently trying to remove an old (20+ yrs.) widespread bathroom faucet that I think is a Price Pfister, and I am stuck. I was able to remove a lot of the handle assemblies, but I am left with what looks like a round threaded washer with four notches in it on top of a plastic washer attaching the faucet to the counter top. It is the same set up underneath the basin as well. When I try to turn it, the entire assembly turns. I am close to just getting a Dremel and cutting the whole thing out. Is ther a special trick or tool that I need? I've included a picture for reference. Thanks for any help you all might have!

The picture is not showing up for me. If you have a dremel with a cutting wheel that's probably the easiest and quickest way to get it off. Either that or hold the valve body to keep it from turning underneath while someone unscrews the retaining nut from the top side.

Those valve bodies are mangled up quite a bit now. Those nuts will need to be cut off.

Those faucet retainer nuts are chemically bonded to the faucet base. I too agree, a Dremel, is the cleanest, and fastest way to remove the retainers.

Best Wishes