Gather your gear.
Each wheel is secured with a nut.
Figure out which side of your tool fits snugly over the nut. Mine is the 9/16" socket.
Apply the laws of "lefty loosey, righty tighty". Your nuts shouldn't be too tight and the wheels slide right off the trucks.
Since your wheels are off, this is a great time to pop your bearings out to clean and lube them. My wheels are filthy and I suggest putting a towel down to put your wheels on to avoid brown circles!
Putting wheels on is similar to taking them off. Make sure your nut is facing the right way.
Apply the same left/righty laws as before, but tighten the nut with your fingers until you can't anymore.
Once you can't tighten the wheel with your fingers anymore, use your tool to finish it up.
Test your wheels. They should spin quickly for 5 seconds or more. If they don't, loosen the nut a quarter turn, testing each time until you get a spin you're happy with.
You may have to loosen/tighten a few times until you get that spot. Try tugging on the wheel after you've loosened it. If it moves or "clicks" a lot, there's a good chance they are too loose.
I just took off my outdoor wheels. I don't have a wheel bag for them so I just put them in ziploc bags to keep them organized and the filth contained from my other equipment.
Repeat on the other 7 wheels. Now go get on your quads and go skate! Happy feet belong to derby girls!