What the steps and procedures in replaceing a timing belt for a 1997 XENissan Quest??

This forum (in my opinion) does not contain sufficient room to fully answer your question.

Having said that, your best bet is to purchase a vehicle specific repair manual that will contain all the required info to perform this task. Shouldn't cost more than $25 at most parts stores.

It's not particularly difficult (main thing to PAY REALLY CLOSE ATTENTION TO is keeping timing marks properly aligned).

Good luck!