* A socket wrench set: To loosen and tighten the belt tensioner. The size will depend on your specific vehicle – check your owner's manual or look at the tensioner itself.
* Wrench (possibly adjustable): Some tensioners might require a wrench instead of a socket. Again, check your car.
* A ratchet: To make turning the socket or wrench much easier.
* Possibly a pry bar or similar tool: This might be needed to help loosen or pry the belt off of the pulleys (but sometimes you can do this by hand).
While not strictly "necessary," a belt tensioner tool would simplify the process considerably. These are specifically designed to apply pressure to the tensioner while you remove or install the belt. However, many mechanics manage without one.
Before you start, consult your owner's manual or an online repair guide specific to your 2001 Buick Regal. This will give you diagrams, torque specifications, and the exact tool sizes you'll need. Improperly tightening the tensioner can damage the belt or other components.
