Don't even need a heat gun - a hair dryer will do. Get some Goo-Gone (to remove the residual adhesive) and some cotton flannel rags and you're good to go. It does require some patience. After removal you will probably have to do some polishing where the adhesive of the pinstripping "bit" into the clear coat.
Do you intend to lift and replace the pinstripes on your car? The reason I ask is because they may have been on the car is 8 years or more ... might find your car's paint has faded leaving you with a darker paint underneath. Just and FYI.