The question I would ask your friend is Why would you want to get reinstated in the first place? As you have read the posts here you will realize that the JW's are a cult. Your friend can find true happiness all he has to do is look inside himself. He does not need any man made organization.
If he really wants to get back in. The elders look at whether he is repented (Translated means, has he done a lot of ass kissing). Regularly attending the meetings and not practicing the wrong doing anymore. After a period of time and if he was DF'd in another congregation, the elders will recommend to the congregation he was DF'd in to be reinstated.
Will
"I am quite sure now that often, very often, in matters concerning religion and politics a man's reasoning powers are not above the monkey's."
Mark Twain