Unless you have some experience with a bead blaster you should not attempt to do it yourself! If the firearm is not prepared properly, and you are not aware of what you are doing you can ruin the gun.
Before undertaking this task, consult you local gunsmith, or if there is one in your area, talk to a plating shop manager. I would bet you can get the job done by a professional as cheap, or cheaper than the cost of equipment and supplies to do it your self.