Drive belt replacement

Yes you can do it.

It should be fine and should be cover under warranty if something happens

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".

Video Tutorial:
https://youtu.be/h4qGOJ5PpSw

The easiest way to replace serpentine \ drive V belt on 2007-2012 Nissan Altima 2.5L 4 cylinders engine:
- remove front wheel on passenger side
- remove plastic splash cover
- user 14mm offset wrench to turn belt auto-tensioner in clockwise direction
- block auto-tensioner from moving using locking mechanism right above the auto-tensioner pulley
- slide the belt off the smooth non-grooved water pump pulley first
and then take the belt completely out
- when installing a new serpentine belt, first hook it onto all pulleys except for water pump pulley. Hook it onto the water pump pulley last
- make sure the new belt is hooked up properly onto all of the pulleys
- unlock the auto-tensioner
Original OEM Part #:
Amazon com OEM 11720 JA00B Nissan Altima Serpentine Belt
Follow this diagram to route the new belt on 2.5L engine:

older model altima need drive belt tension adjustment at 7500 miles intervals, the new models altimas has a automatic belt tensioner.i you hear noises belt tensioner could be failing.or could have leaking coolant getting on drive belt due to water pump gasket leaking or pump leaking.or alternator power steering pump could be failing many things will cause drive belt to make high squeak noises.

the water pump is driven by the timing belt and will require removal or a least losening of the timing belt, this can be accomplished by a knowagable backyard mechanic, with proper tools

Notes Drive Belt Routing

It sounds like your water pump is going it usually vibrates throughout everything if it was your alternator it would show signs with your power the easiest way would to take your belt off remembering the belt route and spin the alternator pulley and the water pump pulley to see if they spin freely without noise

TO REPLACE DRIVE BELT YOU LOOSEN DRIVE BELT ADJUSTMENT BOLT SLIP THE BELT OFF THE CRANKSHAFT PULLEY AND REMOVE IT. IF YOU GOT A 2.5L ENGINE YOU HAVE TO ROTATE THE BELT TENSIONER TO RELEASE TENSION ON THE SERPENTINE DRIVEBELT.YOU NEED A HAYNES MANUAL.IT WILL SHOW AND TELL YOU HOW TO ADJUST DRIVE BELT AND MEASURE THE DRIVE BELT DEFLECTION USING A STRAIGHT EDGE RULER.

OK, went through the exact same thing this week. Put on a new belt, checked for proper seating, etc, etc. and that wasn't it. Read all through this site and others and it comes down to one of two things, the tension pulley assembly or the compressor itself. Seeing as compressors ran about $300 or so and the pully assembly is less than $50 and takes about 45 min to an hour to replace, I did that first. And for me, that was it. Tip for replacing the pulley assembly? Have a wide variety of sockets (depth) and extensions.