As said above, use a mighty vac or speed bleeders. Both availible at your local parts store.
The mighty vac is just a vacuum pump that you use by hand. You crack open a bleeder screw and hook up the hose to it and suck the line dry. Move along till all of them are empty. Then refill the master cylinder and suck till you get fluid. This is my choice since you get all the old fluid out, with little or no mixing.
BTW you start with the wheel furthest away from the master cylinder working to the closest. So Right Rear/passenger rear, driver rear, passenger front, the driver front for bleeding. Same no mater what you use to do this.
Speed bleeders replace your bleeder screws. They have a check valve built in. So you just loosen them and put a hose at the end to catch the fluid. Keep your master cylinder topped off and just pump the pedel till you get clean fluid out.
You must be careful even when changing your brakes, especially if you don't change your fluid not to press the pedal all the way to the floor. You can screw up the master cylinder that way.
What happens is, your pedal only moves so far durning normal operation. Say for 3 years you only move the pedal 6 inches. When you change pads, or bleed brakes, you can push the pedal to the floor if you don't make a point not to. The piston in the master cylinder then travels farther than it normally does. The reason this is a problem is that during its normal travel range sometimes you build up gunk at the edge of its travel path, or even a ridge of sorts that when you push past, will tear the seals on the piston. Thus killing your master cylinder.