low side a/c

I just bought a low side valve that screws into the top of the a/c accumulator on my 1997 Ranger. Quick question: How is the frick do I get the old valve removed? I tried simply taking a pair of pliers to the base of it and turning. That didn't do a thing. I figured I'll try putting some...

I have a 94 ranger that had the lowside port valve loose the piece that closes the hole when done using it. I cant find a new one to replace it. checked 3 different kits from kragen and none of them worked. Thats probly part of my problem going to kragen. the kits are retro kits to switch from...