I have been trying to remove the high side a/c charging port schrader valve on a 97 K1500. the valve is loose and has been unscrewed enough to come out at least 4 times the distance it has to, but still wont come out of the port. Ive tried using a tweezers to pull it out but still wont come out. Is there a trick i don't know about? Is the entire port replaceable or do I have to change all the lines?
The system is already discharged due to a leak at this valve.

 

the port come off you can use the vise grip or there is a socket for it

 

there the part number for the socket gm #90820 just google it