This is something that can be frrustrating because of the tight spaces,
and the shop shouldn't charge too much..  But if you want to do it
yourself, here's how.

There are two belts - one for the alternator and water pump, the other
for the P/S pump and A/C.

It's pretty easy , but you have to pull off the power steering/A/C belt
first, so you might as well do both at the same time.  The two belts
are not identical, one is slightly longer.

The procedure is roughly this:
1. Let engine cool so you don't burn yourself or have the automatic fan
cut off your finger.
2. Loosen hose clamps at each end of the big air horn.  Remove air horn
from the air filter side and rotate the horn up out of the way.
3. Loosen the bolt behind the P/S pulley.  You'll have to get the
pulley in the right spot to get a socket through the slot in the
pulley.
4. Loosen the P/S pump mounting bolt  at the left of the previous bolt.
5. Loosen the P/S pump adjuster lock bolt.
6. Loosen the adjuster bolt so you can swing the P/S pump down and take
off the belt. Mark it P/S to use for comparison to the new belt.

7. Now do the alternator, found on the left.  Loosen the lock bolt at
the center top of the alternator.  Back off the adjuster screw until
you can get the belt off.
8. Put the new Alt belt on, making sure the grooves match up the pulley
grooves.
9. Tighten the belt up  using the adjuster screw until you can only
move it about 1/2" with medium pressure (15 pounds or so).
10. Cinch down the lock bolt.
11. Now put on the P/S belt.
12. Tighten adjuster screw until belt is same tension as in #9.
13. Cinch down the lock nut behind pulley.
15. Cinch down the lock nut on the adjuster arm.
16. Put the air horn back on.
17. Make sure everything is tight and nothing is left hanging around in
the belts.