The things used to remove old adhesive from paint are simple but effective. At any decent auto parts store that sells the 3M adhesive tape, will also sell plastic single edge blades that look like single edge razor blades. Use a hair drier or heat gun on low to heat and soften the adhesive, then scrape it off. Use alcohol to clean the surfaces before applying the new tape. Stuff like GooGone works, but leaves a residue on the paint, it will clean off with alcohol too. It takes a lot longer than using the heat and plastic blades.
I.ve used the heat and blades on every new car I've ever bought to take dealer badging off, it doesn't mark or scratch the paint. Even used it to take off ugly dealer applied pin striping etc. on old paint, there will be like new color underneath.
