Installation Procedure

Install the rear part of the overhead console by inserting the mounting tabs into the roof panel.
Connect the electrical connectors.
NOTE: Refer to FASTENER NOTICE in GM VEHICLES CAUTIONS & NOTICES.
Install the overhead console retaining screws.
Tighten

Tighten the screws to the overhead console to 2 N.m (18 in. lb.).
1. 3.1. Install the rear screws to the overhead console.
  Tighten
  
  Tighten the rear screws to the overhead console to 2 N.m (18 in. lb.).
2. 3.2. Install the front screws to the overhead console.
  Tighten
  
  Tighten the front screws to the overhead console to 2 N.m (18 in. lb.).
3. 3.3. Install the dome lamp lens to the overhead console.
Fig 1: Installing Overhead Console Assembly
Courtesy of GENERAL MOTORS CORP.