Replace serpentine belet on 2002 santa fa - 2001 Hyundai Santa Fe

No familiar with your car, but most tensioners are held in by a bolt going through the center front, or a nut from the back of the unit.

It is on the internet in dozens of places

Take a look at this picture. There should be a slot or square "hole" in the arm of the tensioner....I will also attach a link so you can see how and where this is at.

I'm assuming you mean Hyundai Santa Fe.
Will it start with the belt off ?

Yes. there are basically three ways:

1. Put in a new a/c compressor.

2. Try a smaller serpentine belt. If this model came also w/o a/c, that serpentine belt should work fine. If all Santa Fes came with a/c then like you were saying try a smaller belt. You might have to try different smaller belt sizes(as far as I know) until you really get it right, which is not easy.

3. See if they make an a/c compressor delete pully for your particular model. This is basically just a single standalone pully (dummy pully). Aftermarket companies do not make them for all models, but if they make it for yours, you can use the same serpentine belt w/o a compressor. The internet is the best place to check.

The 2006 Santa Fe came with three (3) different engines, each having different serpentine belt arrangements. The 4cylinder 2.4 lit has three belts, the 2.7 has only one (1) drive belt, and the 3.5 lit has two (2). Go to www.hmaservice.com and register your vehicle by VIN #.. you'll then have access to wiring diagrams, shop manuals, service bulletins, illustrations and procedures, etc.

loosen the tensioner, then put the new pulley on the exact same way the old one came off, then tighten the tensioner back up, it is easy to say, but doing its a different story

First, you need to make sure you have the routing diagram on how to put the belt back on. You didn't mention your engine size, so i have included diagrams for both engines offered in 2002.

4cyl...
6cyl
Now, follow this link to a set of videos that will walk you through the process step by step...
http://www.wonderhowto.com/how-to/video/how-to-change-a-serpentine-belt-on-your-car-39904/

tighten the belt tightener

No,and if this is the original belt it has well and truly past its 'use by' date..