So again, my truck is a 1993.... The last year for R-12 refrigerant... LOL so if it craps out, I either pay through the nose, or risk death in Mexico because some ******* in CA decided R-12 hurts earth... it’s been 20 years... thankfully there are millions of these trucks driving and sitting in bone yards with R-134A AC systems. I was wondering how involved I need to get to switch my refrigerant... can I simply change the compressor & lines and flush the system somehow, then refill/recharge it? Or does everything need to come out? condenser, compressor, evaporator, that drip canister, the AC box behind the entire dash... let me know if I’m missing anything. This is my first AC vehicle, and it’s pretty awesome.... got to keep it alive. thanks!