yucky brake fluid

The safest method is to extract as much old fluid as possible from the master cylinder reservoir. Refill with DOT 3 from an unopened bottle. Block the brake pedal so it stops about 2" off the floor. Have someone hold the pedal down and open the right rear bleeder screw. Tighten the screw and release the pedal. Wait ten seconds and repeat. When the fluid runs clear, move to the left rear, then right front and left front. Be sure to keep the master cylinder reservoir full while bleeding.

This is simple. Put the truck on jack stands, remove all wheels. Put something under the each position. Open all four bleeders. Make sure you keep brake fluid in the master cylinder as you do this. When you see clear brake fluid coming out you no longer have "yucky nrake fluid". You don't need to do a pressure brake flush. We have gravity, therefore a gravity brake flush. Now this could take around 30 minutes or more and about a quart of brake fluid.