weatherstripping question

[dave`12]

I'm replacing my door weatherstripping. There is contact cement residue on the the door frame that is proving to be almost impossible to remove, I have tried wd-40 and goo gone. Also tried a heat gun and a popsicle stick, but paint started coming off.

Is it really necessary to remove all this stuff? I'm thinking if the cement is on so good, that my new 3m weather stripping adhesive will stick to it?

Perhaps I'm wasting my time for nothing here!

It's not in big globs, but some is just about everywhere.

thanx