Source: TruckForums
1. Remove the bolt at the top center of the backside of the tailgate with an adjustable wrench turned counterclockwise. Carefully pry the plastic trim surround on the tailgate handle on the front of the tailgate with a door panel removal tool. Pull the surround away from the tailgate. Be careful not to scratch the surrounding paint.
2. Turn the locking clips that hold the two tailgate latch rods counterclockwise. Pull the rods sideways from the tailgate handle.
3. Remove the two bolts that hold the tailgate handle in place with an adjustable wrench, turning counterclockwis. Pull the tailgate handle assembly from the tailgate.
4. Push a new tailgate handle into the cavity from the front of the tailgate. Replace the two holding bolts and tighten with an adjustable wrench.
5. Insert the latch rods back into the locking clips on each side of the tailgate handle. Rotate the clips clockwise until they lock into place. Push the plastic trim surround back to the outside of the handle until it snaps into place. Replace the holding bolt from the other side of the tailgate with an adjustable wrench turned clockwise.