This document provides instructions for draining and filling the cooling system of a 2009 Chevrolet Express using either a static or vacuum fill method. The static fill method involves draining the system, filling it with coolant through the upper radiator hose, running the engine to circulate coolant, and checking coolant levels. The vacuum fill method uses a vacuum tool to draw coolant into the system and remove air, ensuring proper fill without air pockets. Both methods specify using a 50/50 mix of DEX-COOL antifreeze and water, and checking coolant concentration after filling.