The first step for replacing the transmission on a Chevrolet Malibu is to lift the hood and carefully disconnect the battery to prevent shocks. Next, chock the back wheels, and raise the vehicle using a professional jack or two smaller jacks placed under the front corners.
Use an engine hoist to chain the engine in place and prevent it from falling after removing support bolts. Disconnect the motor mounts that hold the engine in place; make sure the engine is secured while doing so. Disconnect the lug nuts by the front wheels by unbolting them, and either poke them out of place of use a blower to remove them.
Next, remove everything connected to the transmission, including the electrical connection, the shift linkage and the air intake. Using a drain pan, remove the power steering fluid, and dispose of it properly. Carefully remove the bolts connected to the transmission drain pan to drain the fluid, then reconnect it. Finally, disconnect the suspension support, and carefully lower the transmission.
Perform the steps above to install the new transmission. Fill the new transmission with the prescribed amount of fluid, and let it work through the system. After lowering the vehicle, make sure the parking brake is on to prevent the vehicle from rolling if the transmission is not connected properly.