This is a pretty good video for anyone who has never been inside an alternator. Includes some 4G hacks & tips.
Diagnose bad alt video: https://www.youtube.com/watch?v=BS_f...640&height=480
How to rebuild video: https://www.youtube.com/watch?v=OoN6...640&height=480
Parts ($65): https://alternatorstarterrebuildkits.com/product/4g/