It all depends on the bbl. If it is one of ours and is plain-ended or already threded and has a pinned and welded brake:
Call for an RMA (866-980-7625).
Send in the upper half only (along with note describing what you want done and the RMA info).
Approximately $50 plus shipping back to you.
If it has the pressed-on faux flash hider (entry tacticals had it during the ban) there isn't much we can do for you.