Of course not.
There is no need to remove the timing belt to change the thermostat.
You need to remove the plastic panel at the base of the windscreen the filter is located under there.
First you will need to loosen the tension on the belt in order to remove the belt. After that, you will need to remove the bolt holding on the alternator. Installation is the reverse. Dont forget to tension the belt
You will need to remove the front engine cover, on your 1997 Pontiac Bonneville, in order to change the supercharger belt. Loosen the tensioner pulley to remove the belt.
First get a repair mnl then draw a map of the belt routing. You need a belt tensioner tool to start with. You need to remove some of the tanks on that side of the motor.
You need to remove the serpentine belt and unbolt the old alternator. Bolt on the new one and reinstall the belt. Its that easy.
If a windscreen is obtained second hand, it may need to be trimmed to fit your car. Then you must remove the plastic mouldings from the edges of the windscreen. Then the windscreen is primed for the caulking and placed in the car. It is best to use gloves during this process.
if you just want to change the belt put 1/4" drive extension into the tensioner to release belt,then you need to take tensioner off...2 10mm bolts...remove tensioner & slip belt off...you may have to remove air ductwork for access
To remove the serpenteen belt on this vehicle, you must first locate the spring loaded tensioner. You will need a 1/2" breaker bar or a socket to recoil the spring load. doing this will release the tension on the belt. You can then remove the belt. NOTE: If you are just changing the belt with a new one, DO NOT remove the tool until the new belt is in place. You should not have to remove any parts to change the belt.
All you have to do is loosen the acessory that is driven by that belt. There is an anchor bolt and a pivot bolt that need to be loosened then the belt will slip off. Of course if the belt is "under" another belt, then you will have to remove that belt as well.
You must remove the crankshaft pulley (19mm socket) and then the timing cover but it appears to need the engine jacked up, to remove the front to frame mount to get the new belt in.
Because if dies on you after you have replaced the timing belt it will cost as much as replace the timing belt. If you do not know, in order to remove the water pump you need to remove the timing belt it's about $300-600 depending where you live. Do you really want to pay such money twice?