the compressor isnt too hard to change. the problem is recharging. after you assemble the system you can rent the "gauge manifold" and "vacuum pump" from autozone. itll take a few days as they dont stock these loner tools in their stores they will come from their warehouse but it is still a loaner tool. then use the gause and pump to put the systme in a vacuum. run the pump all night if you want. you can never have to good of a vacuum. then charge the system with the right amount of refrierant. i stress the RIGHT amount. too many people ocercharge for a cooler ac unit but that only leads to shortened compressor life and the unit will take more horsepower to run its actually a lot easier than it sounds
