I used Goof Off and it came off pretty easily. I've seen a video where a guy painstakingly removes with acetone using like 50 Q-tips over the course of an hour. His reasoning is to avoid damage to the plastic. With Goof Off, I use paper towel, do some broad wipes, rinsing the leg off every few minutes to make sure there is no plastic damage. Then I get the crevices with Q-tips. Then a last go over with paper towel and rinse. Took me about 20 minutes and it improves the figure drastically.
After that, the set was worth it for me

Twice over - and now I have the best Punisher Ever (for now) and an Animated Series Punisher.