The blend door actuator on a 2001 Chevy Malibu is located
inside the dashboard, behind the glove compartment. Access requires removing the glove compartment itself. This is not a straightforward job and typically requires some disassembly. You'll likely need to consult a repair manual specific to your 2001 Malibu to get detailed instructions and diagrams showing the exact location and removal procedure.
Important Note: Accessing and replacing the blend door actuator is often a difficult task, requiring significant mechanical aptitude and potentially specialized tools. If you're not comfortable working on car interiors, it's best to consult a professional mechanic.