you can get a new gasket, but do not bother with it since a whole new fitting will be easier to install. Buy a new 2″ closet spud and then try to unscrew the old one. It should twist out of the bowl. Then you can insert the new one and tighten it up. You will want to have the flush ell inserted into the spud before you assemble it otherwise getting it together, without previous experience, can be frustrating.