Hi bk - What you are trying to do is to bring the pressure in the pot up to about 60lbs and hold it.
I've modified three now and I start by taking all the parts off from the inside and the outside. I use one of the available "ports" for the pressure relief valve, and another port for a "tree" that has an air hose connector, a shut off valve and a pressure gauge. If there are any more "ports" I plug them with metal screw in plugs. All of the connections are sealed with 8 turns of Teflon tape. I usually put a 90 degree elbow on the inside of the lid where the air comes in, so that the air is deflected to the side and doesn't blow your resin out of your molds.
I hope this helps, let me know if I can help more.
Happy turning
Tom