Picked up my custom ordered truck yesterday and it sits on my driveway with only 45 miles. As soon as I read about the blackout tape, I new it was coming off.
Today I had to finish stripping the old truck and had some time off. Just looking at the truck decided to go ahead and remove the tape. Did one side tonight, other side when the weather allows. Definitely like the look better. Don't see how removing could have any effect on the warranty, but do at your own risk.
Couple things deviations from the way everyone else has done. Once I started it, I used a pair of pliers working it very slowly and small grabs on each pull. Didn't save any time but sure did save my fingers. When removing it at the window side, found to open the window and push the tape slightly towards the inside which made it just pop loose. A couple places behind the trim it started to tear so I very carefully used a screwdriver to push against the tape to get it started again. Since the tape isn't pushed hard in those areas, it isn't very tight.
As the others have mentioned, do it when it's warm. I started the front door when it was about 70*. By the time I got to the back door it had dropped to about 60* and the job was a lot harder. I'll be sure to have the other side in the sun when it gets done.
And I wouldn't worry about the paint. My old truck is 10 years old and the tailgate has been in the garage for most of that time yet still matches the rest of the paint perfectly.