Get it done before it get's too HOT, Trust me!!!!! Take your time, especially on the tape. If you are just doing the underside of the flares it's not too bad. But if you do the entire bottom like I did it takes probably 3x's as long. You have to tape off inside the door jams too adding a lot of time.
If you are still trying to get off the sticky stuff I recommend Simple Green. Oh and make sure you get those edges good, the hot weather and just scuffing the paint instead of using a light sand paper caused some problems on my edges in a few places. I had to go back and touch them up and so far the edges are holding up great.
Here are some pics of my install:
LINK