You have to understand how A/C works and look at it as a system. Using the brake analogy again, if you don't bleed all the air from the system it won't work, and it's the same for air conditioning.

In the scorching heat of summer, the temperature inside a parked vehicle can rapidly climb to over 122°F. The most effective solution for cooling the interior is the air conditioning (A/C) system ...

On a 1-5 scale, 5 being nasty hard and 1 being wiper fluid or tire rotation, how hard is yanking and replacing an A/C system? Car is a 4-banger with manual transmission and not a ton of underhood ...