To install a Chevy idler arm, remove the old arm, remove the bolts, separate the idler arm from the centerlink and then install the new one by bolting it in. If the Pitman arm requires a replacement, this is also a good time to do so.
To start the job, jack up the vehicle under the A-arm on the right, and remove the wheel. Use a 6-ton jack stand and a floor jack for extra safety protection. Remove the cotter pin from the idler's nut, and then remove the nut. Remove the bolts that hold the idler arm to the frame, and then separate the idler arm and centerlink with a Pitman puller. If the Pitman puller does not fit, remove some of the metal from the inside until it does.
If replacing the Pirman arm, do it now. If not, use a new cotter pin, making sure it matches the old one, and do this by trimming it with pliers. Place the bolt of the idler arm into the centerlink, and then put the new bolts through the frame, ensuring to place washers under the bolts. Position the arm in a way so the frame bolts slide into the hold. Install the washers and nuts, and then torque to the vehicle's specifications.
Place and tighten the large nut onto the idler arm centerlink bolt. Tighten this bolt to specifications in order to line up the cotter pin hole. To align the holes, always tighten, and do not go backward. To finish the project, put the new cotter pin into place, and apply grease to the arm.