Bend the lip of the seal out far enough to grab it with a small pair of vise grips- - - -- -then pry on the vise grips. I've also replaced the tension screw on a vise grip with a long piece of all thread rod and used a big socket as a slide hammer over the rod.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!