Remove and install bracket at AC housing - AR83.30-P-5200-01GM

Fig 1: Identifying AC Housing Bracket Components

Courtesy of MERCEDES-BENZ USA

Open all cable ties (1).
Expose wiring harness.
Unscrew nuts (2).
Unscrew nuts (4).
Do not loosen the nut (4) at the elongated hole, otherwise the seal between the air conditioner housing at the firewall is no longer guaranteed and whistling noises may occur following installation.
Remove AC housing bracket at floor panel (3) together with AC housing bracket at bulkhead (5).
Install in the reverse order.