I need instructions for replacing the serpentine belt in a 2004 Maxima. AND I need instructions for replacing the power steering belt in a 2004 Maxima.

It is all guesswork, but there is either an alignment issue due to the crash or the power steering RACK is damaged and causing stress on the pump and the belt.

My Advice, get a lawyer on it and take the dealer to court. The fact that it was a write off should have been disclosed at the time of the sale. Get your money back, or credit on another vehicle.

https://www.bing.com/search?q=2004+grand+prix+serpentine+belt+diagram&form=EDGNTC&qs=AS&cvid=738d3f0931444115b44f6f066f182f85&pq=2004%20grand%20prix%20ser

How To Change The Serpentine Accessory Belt On Nissan Maxima Altima Etc

Nissan Drive Belt Tensioner and Belt Replacement 3 5 Front Wheel Drive

There are several videos on how to change out the serpentine belt For more info just do a web search " 2002 Nissan Altima serpentine belt replacement".

Sounds like the power steering pump has failed.
You could take the serpentine belt off and check the pump pulley.

So you have done all this so far?

1. Disconnect and isolate battery negative cable from battery post.
   
2. Siphon power steering fluid from pump reservoir.
   
3. Remove air cleaner housing and inlet tube to throttle body.
   
4. Remove serpentine drive belt.
   
5. Remove hose clamp, then supply hose from pump.
   
6. Unthread tube nut, then remove pressure hose from pump.
   
7. Remove three pump mounting bolts through access holes in pulley.
   
8. Remove pump from engine bracket.
   
9. If pulley needs removal
   

belts dont just "snap" find out what happened. there will be bolts and slots to loosen and tighten PS belts on pump, and a tensioner pulley on th ealt belt. on the idler.

The power steering pump will have a tensioner you need to loosen. Then for the other belt. There is a tensioner located on the pass side. You can see it if you look down the pass side of the engine.

you need to remove the front belt to even get to the rear belt.  Try accessing it from underneath.

Yes. One for the timing belt, and one or 2 for the serpentine belts.

Sounds to me that the power steering belt is loose. If it is a 2.4 litre engine it has two serpentine belts. You should replace the belts especially if it was smoking.