I was playing the game and I was trying to go for the achievement where you put the 10 masks on zombies. So I was in the toys shop in Paradise Plaza and I accidentally put a bear head on my head. I want it off now! But I don't know which button to push. It's really annoying to see Frank in the cutscences with a bear head. Funny at first but now annoying. HELP!

I'm sure you figured it out by now, but if not... When you put something on, pressing the action button again will return the item.  You can also restore your default image for all items at any bathroom.  Replacing the item with an item of the same category (in your case, another face or hair item) will also make it go away.

I love making Frank look like a jackass.
I had him barefoot with a little tight t-shirt and some small shorts on.
Funniest thing about that game, either then the game itself.

I've created an entire character out of the dressing mechanic.  Sexy Bear. 

Bear Head. 
White Suit. 
Science of Sexuality.