alt is east to remove, take the pos cable off the battery,take the belt off, remove the thick cable bolted to the alt, and the plug. then take the 2 bolts off that hold it on the bracket. lift it off.
when you put the new one on, the cable you bolt back on, do not make it super tight, snug, plus a 1/4 turn tops. the threads are a stud that are only soldered on, if over tightened it brakes free, and your out of luck.
if you have a local re builder by you, they are usually cheaper than any parts store. most of these shops rebuild starters and alternators. sometimes they have them on a shelf waiting to be sold, (they want your old one, or charge a core charge) and sometimes you need to wait a few hours to have yours re built.
if you do go to a parts store they will want your old one too, or they charge a core charge for it. so what i do is take it off at home, bring it to the store, make sure it matches up perfectly to the old one, then buy it. and no core charge because your leaving the old one there.
