First I would figure out why it needs to be bled, if it was leaking somewhere, or fluid low, new caliper, etc.Brake
bleeding is the procedure performed on hydraulic brake systems whereby the brake lines (the pipes and hoses containing the brake fluid) are purged of any air bubbles. This is necessary because, while the brake fluid is an incompressible liquid, air bubbles are compressible gas and their presence in the brake system greatly reduces the hydraulic pressure that can be developed within the system.
The process is performed by forcing clean, bubble-free brake fluid through the entire system from the master cylinder(s) to the calipers of disc brakes
or the wheel cylinders of drum brakes). The brake bleeder is normally mounted at the highest point on each cylinder or caliper. Brake bleeding can be done easily by two persons working together and doesn't require much technical expertise besides a basic knowledge of brakes and car hydraulics. One wheel at a time, the brake bleeding valve for that wheel is opened while a drain hose is attached to that valve and immersed into a pool of brake fluid. The assistant then pumps the brake pedal. In this manner, fresh fluid is forced through the system into that wheel's caliper or wheel cylinder, and any old, dirty, water-saturated or bubble-entrained fluid is expelled from the system. When the fluid from the caliper or wheel cylinder runs clean, clear, and bubble-free, the brake bleeding valve is closed and the drain tube removed. The process is then repeated for the remaining wheels. During the entire process, the brake fluid reservoir must be kept full of fresh fluid lest new air bubbles be introduced into the brake system. (As found on Wikipedia)
It would be important to note that the person pumping the brake should press slowly and tell you when they are nearing the end of the pedal stroke to you can close the bleed valve before you **** air back into the system. REMEMBER to keep brake fluid in the reservoir at the master cylinder
Hope this helps. It's pretty easy and best done with 2 people, they hav vacuum bleeders which can be done with 1 person but the results are not consistant or perfect.