Brewology

This is partly about my recent activity in programming 12f685 PIC's, but does anyone know like a tutorial or a fairly decent program that can disassemble .hex files back into the .asm files that were used to compile it? I would like to make some minor adjustments to a code I programmed to a PIC for my xbox 360 rapid fire controller, and add a function for lighting up the 3rd player LED when it is active since it isn't in the specific hex file I used, and maybe even adjust the fire rate in tenths of a second instead of just seconds.

But yea, any help on the topic of what program/how to disassemble .hex files would be awesome and earn you some rep. :p