Redwood, thanks for the reply.
Bought the valve seat wrench from Lowes and easily took off the 3 valve seats. Upon putting on the hot stem valve seat, the first one I did, I realized it wasn't screwing in correctly - the threads not matching correctly or something. Spend 20 minutes trying to get it out but just couldn't. Thought perhaps the valve seat I had was worn out or maybe it was the valve thread. The other 2 valve seats were replaced without issue. After some random fiddling and lots of luck, it finally came out. Replaced it with the diverter stem seat valve knowing that seat valve was fine. However, it also didn't sit correctly; very loose and again wouldn't come out. Thinking some teflon would help, I tried to take it again but gave up when it turned 1:30 AM.
Any recommendations? I guess if I don't get a response I'll replaced it - probable with a Delta 1700. Installed a Meon Posi-Temp downstairs couple of years ago but I figured I'd take everyone's suggestion from other threads on this website.
Side Note: Great website .. well actually great people!
Thanks again everyone!