heat gun on low "LOW" or a hair dryer on high. you can test your heat gun on a piece of electrical tape.. if it bursts into flames its way to hot.
I did a bunch of this tape removel and the key is to to do a foot or two at a time
keep the heatgun moving never hold it in one spot. I then used some goo gone on any residue, cleaning as a went along to remove the goo gone.