[b]Replacing the MC is pretty straight foward.
First loosen and retighten the line fittings to the master cylinder.
Remove the two nuts that hold the master cylinder to the vacuum brake booster, and remove the line fittings.
Remove the master cylinder.
When you get the new replacement master cylinder, there should be instructions with it explaining how to bench bleed the new master cylinder. DO NOT SKIP THIS STEP.
After bench bleeding the new master cylinder, install it onto the brake booster and connect the line fittings. Top off the master cylinder with brake fluid.
Have someone pump the brake pedal, and then hold the pedal down. Now crack open both line fittings at the same time to bleed out as much air as possible. Retighten the fittings before the brake pedal is allowed to come back up. Repeat this a couple of times.
Now bleed the brake system at each wheel following the proper sequence for your vehicle.
Check for a solid brake pedal.