I've done it once. I used the Autozone Vehicle Repair Guide to show me how. You need to register, but it's free. Here's the short write-up.
1. Raise and support the truck on jack stands.
2. Remove the torsion bar cover plate.
3. Measure the exposed length of the adjusting nut for reinstallation.
4. Use a special tool to release the tension off the adjusting bolt and remove the adjusting bolt. I used a 2-jaw gear puller, but this is dangerous as the jaws can spread apart and the tool can literally shoot off. The special tool has a retainer bolt to prevent the jaws from spreading.
5. with the adjuster bolt removed, remove the bar nut.
6. Release the tension from the bar by backing off the special tool. Once the tension is relieved, the bar can be lowered and pulled from the LCA.
Reinstall is in reverse, with the adjuster bolt being reinstalled at the measured length.