Corroded/stripped faucet seat

[Toy4x4]

I did a little maintenance on the tub faucets and found the shower director seat stripped and corroded.
Is there a trick to get these off or a different tool to solve it? The regular wrench just spins. Since I changed out the rest of the parts, the shower now dribbles even when the water is shut off to it. I guess the old washer had a better seal or I knocked a bit off the seat when trying to take it out.
Thanks!

 

[ag_ghost]

You may need something like this?
https://www.google.com/search?q=plumbing+valve+stem+socket&ie=utf-8&oe=utf-8
Kevin

 

[Stelth]

There are a number of extractors available, including left-hand thread "easy out" types. I've also had success hammering a slotted screwdriver into the stripped hole, and unscrewing the seat by gripping screwdriver with a pair of channel locks'

 

[abycat]

I use an Allen wrench to replace seats. Sometimes you need to put vise grips on them for added leverage. I forget which size wrench but if you have a handle set just try a few out.