I have an '06 Lariat that had the "4X4" stickers where your FX4 decals are. My truck is black so it heats up pretty hot in the sun.
All I did was park it outside on a sunny day and peel them off slowly.
Then I turned it around in the driveway, waited 2 hrs. and did the other side...
Whats wrong with the hair dryer? Is it possible that theres a clear coat painted on top of the decal??
Loaded like a freight train, flyin' like an aeroplane, feelin' like a space brain one more time tonight...