I'm new to the trade, and am interested the proper steps to change out a condensing unit that is old, or not working. Where I work we remove the old unit and throw in the new one as fast as possible. We do recover the r22 if it hadn't leaked all out but the guys don't do anything else. I feel there should be more to it. Maybe to make sure the rest of the unit is working? Please let me know step by step the proper way to do this.