How and where?
Fett is a bounty hunter, this is something Lucas seemed to forget the moment the credits for ESB rolled back in 1980.
For me the only use that makes sense is the scenario where he sells the Emperor's location to the Rebels and sells the Rebel's presence in the Imperial trap to Vader.
That way he is consistent with the character we see in ESB.
Otherwise leave him out all together, in a number of edits he is proven easy to remove and not that missed to be honest.