You need a pair of these
There is a spring inside of that circle deal that holds the connection together, you'll put the pliers on the pipe and they'll go inside the circle deal and you should feel it compress a spring, then you should be able to pull your lines out.
As for the second picture, That black piece is a cap that screws off, correct? if it is, than thats the High side charge port. its how you charge the A/C in your truck. another special fitting, like the recharge kits you see at Napa, only bigger. i have one in my tool box somewhere but they don't recommend you charging your A/C from the high side.