Rust on my MVC2 Bolt

I just ordered new buttons for my fightstick and I got them in today. I watched videos on youtube to make sure i dont make any mistakes while replacing my buttons. So I start to taking the bolts out and the very last bolt wont come out. I know why its stuck is because of the rust, so when i use an allen wrench it doesnt work. all the allen wrench does is go in circles and now im frustrated. can someone please help!!! (fyi i have sweaty palms and i think that might be the cause for the rust… i think)

In auto part stores you can get stuff that breaks apart rust for bolts.