Lever broke and I pulled out the stopper which looks like a brass piston because it was not draining. I thought if I pulled that out it would drain but no. Plunged it to with no luck.

Hi Johnny

Stick a wet rag into the overflow pipe (plate removed) and try using the plunger again. Here, by blocking the overflow, plunging will now direct the air down the drain and not up the overflow.

If that fails you'll need to purchase a hand-held snake machine and snake the drain (through overflow or through cleanout in Ptrap in basement).

Mark