105 is cassette .... screw up one if those is really hard. Those hubs and freehub body is super easy to take appart with 3 tools, wonder what they did?????
Stupid people... well the good news is that all those 8sp ones are the same, even the MB one. Just swap it. Done. Dura ace i believe is slighty different internally and may it wont work but im not that sure.
Sheldon has a page with the details. look for it or simply get a new hub, it wil lbe cheaper in the long term.
Don't ever come back to that lbs. Do the stuff your self.