Release the headspace pressure in both kegs. Make a jumper line, a piece of beer line with a liquid QD on each end. Connect it to the liquid posts of both kegs. Apply gas pressure to the keg you want to transfer from, and pull the pressure relief valve on the keg you want to transfer to.
I'm trying to find some porn filmed by a dog wearing a GoPro. - SharonaZamboni
Hunter, when you get bored, will you put a taco in my elephant's hands for me? - Hat