1990 Air conditioning compressor blown?

I have a 1990 Ford Taurus, with the A/C system retrofitted to 134a. It started blowing warm, so I went to recharge the system thinking it had a leak. When I hooked up the hose and guage to the LP connection (back near the firewall) the guage was reading really high numbers. I could then hear the compressor clutching into and the LP side pressure rose even further to over 100 psi. I am guessing that either a gasket in the compressor is shot or the compressor valves are busted and the HP side is discharging into the LP side. Can I take the compressor apart to find the possible solution, or do I need to replace the whole compressor? How hard is it to replace? Is it worth the headache?

THANKS!!

a similar situation is described in the following link:

http://www.airconditi on.com/wwwboard/alternative/current/6703.html