In one of the tutorials we already published on our webiste we talk about alternator repair. Once you've made the needed repairs on the alternator (or replaced it with a new one) the next thing to do is put it back. The tools you need are the same as with taking off the alternator. Here's the procedure:

1. Put the alternator in place. Do it carefully, especially if it's in a tight position.
2. Put the lower screw that anchors the alternator to the motor. Be sure that it goes all the way through. If it resists, wiggle the alternator with your hand.
3. Put the upper screw on (the one that goes on to the tightener).
4. Put the belt on. Make sure that the belt is going around all the pulleys in a correct manner (no risk of twisting or falling off the pulleys).
5. If the belt tightener is spring-driven (self-tightening), first tight both of the screws and then put the belt on the pulley. Release the tightener with a wrench. If not, put the belt on and use a lever to do tighten the belt.
6.  Once the alternator and belt is in place, put the wiring back where it was. Most alternators have a connection jack which matches the slot on the alternator housing. You can't make a mistake there. If the wires are separated, be sure to put them back in right order. Mixing them up can cause damage to the alternator and installation. Clean all the contacts with an anti-corrosion spray
   

   Alterntator position
   or sandpaper.
7. Check that the belt has proper tension. It's best if you have a belt-tension gage. If not press the belt, it should have a 1-1.5 cm tolerance at the longest distance between pulleys. 
8. Put the "-" battery terminal back on. Start the car and make sure that everything is OK (no unusual sounds or squeaks from the belt). If there are, stop the engine and check it out immediately.
9. While the car is running, check the voltage feed to the battery with a multimeter. The reading should be between 13.8 V and 14.5 V.
10. Turn off the car and make a double-check on the belt tension, tightening of the screws and nuts and that all the wiring is in place.

Be sure to remove all the tools you've used. Take a look at the installation that goes to the alternator, check that it's loose and there's no threat of damage.