Scott Bryan
You can use a screw extractor to remove seats that have stripped out. If you can identify the brand of faucet you have I may be able to tell exactly what seat should be in the faucet and give you the exact size of extractor you need. Go to our web site and see if you can identify the stem you have and let me know and I will see what we can do.
Good luck,
Scott http://www.plumbingpartsdepot.com
