If I didn't do "most" of my own maintenance and repairs I probably couldn't own a home, vehicles, RVs...in fact I do 90% of the maintenance on a little airplane that I've owned for 35 years. There are some "parts", however, that I've learned (yes, often the hard way
) that are best left to trained and experienced specialists. AC is one...for me...but, if someone is intent on learning by digging in and willing to face either the joy of accomplishment or the agony of defeat, have at it. The latter can be very expensive. Again, don't ask how I know