a/c question
 

Well I charged my a/c on my pacifica yesterday, and ended up with 55psi on low side,
was at 25 when I started. I am going to use my friends gauges and hook up to the low and high side. to get the low side down, do I just discharge from the high side service port.

I would discharge SLOWLY from the low side. It has positive pressure so it will discharge. The high side can run up to 200+ psi. Discharging from there could release much needed oil since it will tend to come out rapidly at those pressures. You can also lose oil from the low side but can control it better there. The oil is carried in suspension in the freon so releasing from the high side which is when the freon is liquid will release that oil, releasing slowly from the low side where it is a gas, and if done slowly, shouldn't release much if any oil.