Removing Compressor to Condenser a/c line

[PeterInSTL]

Any tips on removing the hex nut that holds on the a/c line to the compressor. I am trying to use a T-shaped hex wrench (is their a better tool), but I cannot budge the bolt :( . It has probably been on their fir 14 years. Tried using lubricant to loosen it but no luck. Any suggestions would be appreciated.

Thanks