Removal Procedure

WARNING: This page is about a different car, the 2004 GMC Sierra, 2004 GMC Cab & Chassis Sierra, 2004 Chevrolet Silverado, and 2004 Chevrolet Cab & Chassis Silverado. However, it is still accessible from the selected car via links, so may be relevant.

Remove the energy storage box (ESB) intermediate cover. Refer to Energy Storage Box (ESB) Trim Cover Replacement (5.3L Engine w/RPO HP2) .
Cut the tie straps (1) securing the power cable to the ESB.
Remove the power cable nuts (3) from battery 2 and battery 3.
Remove the power cable (2) from battery 2 and battery 3.

Fig 1: View Of ESB Power Cable, Tie Straps & Nuts (Battery 2 To Battery 3) (5.3L Engine w/RPO HP2)

Courtesy of GENERAL MOTORS CORP.