washer tub seal replacement?

How do u replace the tub seal. I ordered the seal today because water was coming out from the bottom of the center, but im not sure u you need a seal puller or not to remove old one. And also i assuming to put the new one on tighten the bolt will pull the seal in place on the shaft? Can some one please help me.

Thanks, Pat:mad:

A model number may help others help you