need help as soon as possible

[jrs86gn]

i am in the middle of replacing my power master with a vacuum system. i have the power master off but the bracket that holds it to the fire wall wont come off. i have threw of the four bolts off. but the forth bolt dosent have a nut on it, it has some kind of washer holing it on. i have no idea how to take it off. any help would be greatly appreciated trying to get the car done this weekend

 

[novaderrik]

can you get a pic?

if it's the kind of washer i'm thinking of, you just need to get a screwdriver up there and mangle it until it falls off.