1- wait for a hot day
2- find the following: fishing line, some sort of lube, and towel (for wiping lube), and a heat gun or hairdryer in a pinch. and googone.
3- heat molding
4- spray a bit of lube along top of molding so it soaks the 3M **** under it
5- slowly rubn fishing line behind molding, pulling it out and back (or forward), SLOWLY
6- molding off
7- use goo gone to get rid of excess tape
8- rewax door
your paint may be slightly mismatched where the molding is due to sun exposure, so keep that in mind. Mine wasnt after 5 years, but every car is different. Also, go slow because I have seen a couple cases where the paint was ripped off the door by going to fast, or using too much force.
-2002 Mustang V6: Supercharged and such
-1997 Mustang GT: bolt ons
-1969 Chevelle SS396: 502 crate, TH400