Installation Procedure

Loosely install the rear support bracket onto the cross sill studs using the 2 nuts and 1 screw through the rear pillar assembly.
Loosely install the forward bracket onto the pickup box cross sill studs using the 2 nuts.

Fig 1: Locating Forward & Rear Support Brackets-To-Pickup Box Cross Sills
Courtesy of GENERAL MOTORS CORP.
Position the step panel over the brackets using the following steps:
1. 3.1
  
  Slide the rear inboard tab around the rear pillar assembly.
2. 3.2
  
  Slide the step panel under the side outer panel.
Install the rear step panel to the side outer panel using the 4 push-pin fasteners.

Fig 2: Removing/Installing Step Panel
Courtesy of GENERAL MOTORS CORP.
Loosely install the 1 screw through the forward bracket into the step panel.
Loosely install the 3 screws through the top of the step into the rear support bracket.
NOTE: Refer to FASTENER NOTICE in GM VEHICLES CAUTIONS & NOTICES article.
Torque the following fasteners in the specified order while pushing the forward and rear support brackets upward.
Tighten
1. 7.1
  
  Tighten the rear pillar to rear support bracket screw to 9.0 N.m (6.6 lb ft).
2. 7.2
  
  Tighten the forward support bracket to step panel screw to 9.0 N.m (6.6 lb ft).
3. 7.3
  
  Tighten the forward and rear support bracket stud nuts to 25 N.m (18.4 lb ft).
  
  Fig 3: Locating Step Panel-To-Forward & Rear Support Brackets Screws
  Courtesy of GENERAL MOTORS CORP.
Install the 1 screw in order to secure the step panel inboard tab to the pickup box rear inner pillar.
Tighten

Tighten the inboard tab screw to 1.5 N.m (13.3 lb in).

Fig 4: Locating Step Panel-To-Pickup Box Rear Inner Pillar Screw
Courtesy of GENERAL MOTORS CORP.
Install the forward brace to the forward support bracket using the 1 screw.
Tighten

Tighten the forward brace to forward support bracket screw to 9.0 N.m (6.6 lb ft).
Install the forward brace to the step panel using the 1 screw.
Tighten

Tighten the screw to 9.0 N.m (80 lb in).

Fig 5: Locating Step Panel Forward Brace
Courtesy of GENERAL MOTORS CORP.
Install the filler plate using the 2 push-pin fasteners.

Fig 6: Locating Step Panel Filler Plate
Courtesy of GENERAL MOTORS CORP.
Secure the splash shield to the rear step panel using the 3 push-pin fasteners.
Torque the 3 step panel to rear bracket screws from Step 6.
Tighten

Tighten the screws to 9.0 N.m (6.6 lb ft).

Fig 7: Locating Wheelhouse Splash Shield
Courtesy of GENERAL MOTORS CORP.
Install the step pad to the step panel using the following steps:
1. 14.1
  
  Insert the locator pin on the pad into the hole in the panel.
2. 14.2
  
  Press the snap tabs on the pad into the holes in the panel.
  
  Fig 8: Locating Pickup Box Side Panel Rear Step
  Courtesy of GENERAL MOTORS CORP.
Install the rear brace to the rear bumper bracket and step panel using the 2 screws.
Tighten

Tighten the rear brace screws to 9.0 N.m (6.6 lb ft).

Fig 9: Locating Step Panel Rear Brace
Courtesy of GENERAL MOTORS CORP.