Changing tire is simple, usually, with a bit of practice.
I used to race hare scrambles, and if you can't change a tire on the side of the trail, with the tools you are carrying, in less than 12 minutes, don't bother coming out.
I installed a pair of Michelin Road smarts the other day mostly with just my hands. I used the spoons on the top of the back side. It took about 15 minutes to install two tires. (I am 62 years old with arthritis and nerve damage in my hands. What's your excuse?)
I keep a bottle of dish detergent (for some reason Dawn dish detergent works best) and water to use as tire lube and to wash my hands when I'm finished (it's something that comes in REAL handy trackside and you use it to lube or wash LOTS of stuff. Don't leave home without it). I wouldn't use windex as it contains ammonium, which will harden the tire rubber.
To set tire pressure: Unless otherwise indicated, you want the tire pressure to increase 10% when the tire gets up to operating temp.
Check the cold tire pressure before you go out, then check the pressure IMMEDIATELY after getting off the track.
If you went out at 30psi and return with tire pressure at 33psi: you're golden.
If you go out at 32psi and return at 34psi; drop pressure (less air= more tire flex = more heat = more air expansion) and try again.