Installation Procedure

Install 2 nuts on the roof bow and a nut to each side rail.
With an assistant, position the sunroof to the roof.

Fig 1: Installing 2 Nuts On Roof Bow And Nut To Each Side Rail
Courtesy of GENERAL MOTORS CORP.
Use the sunroof retainers in order to secure the sunroof to the roof.
The sunroof retainers are used in order to assist in the assembly of the sunroof at the assembly plant. If a retainer is broken, do not replace the retainer.
Ensure that all broken retainer pieces are removed from the vehicle in order to prevent a rattle noise.
NOTE: Refer to FASTENER NOTICE Cautions and Notices.
Install the bolts that retain the sunroof assembly to the roof.
Tighten

Tighten the sunroof mounting bolts to 9 N.m (80 lb in).
Install the sunroof drain hoses to the sunroof assembly. Refer to Sunroof Drain Hose Replacement - Front
Install the headliner. Refer to HEADLINER REPLACEMENT (PICKUP) or HEADLINER REPLACEMENT (UTILITY) or HEADLINER REPLACEMENT (EXTENDED CAB PICKUP) .

Fig 2: Installing Sunroof Assembly To Vehicle
Courtesy of GENERAL MOTORS CORP.
Perform the following steps in order to adjust the sunroof glass, as needed:
1. 8.1. Loosen the screws that retain the sunroof glass to the sunroof assembly.
2. 8.2. Secure the sunroof glass in position by tightening the screws.
  Tighten
  
  Tighten the screws to 3.5 N.m (31 lb in).
  - Adjust the fit between the sunroof glass and the roof opening.
    The fit should be equal on both sides.
  - Adjust the rear edge of the glass slightly higher than the front edge in order to minimize wind noise.
Open and close the sunroof.
Reinspect the fit of the sunroof glass.