Here's the link with helpful instructions at top, and there's another post a little further in with with a step-by-step in pictures.
The original file's been taken down, so you want to follow the instructions looking for it on a mirror site.
If you try a little, and still can't find it, post back in THAT thread and one of us will gladly help out.
And don't get discouraged by people giving you a hard time over an honest question. We all get that.
http://androidforums.com/htc-evo-4g/138034-official-how-manually-apply-froyo-2-2-update-3-26-651-3-htc-evo-4g.html
This is the battery thread, so I won't be looking for your questions on that here.