Windows Phone Forums at wpcentral.com - View Single Post - 8773 force update possible? (like 8107) This is the post that I referenced when doing the force update. Because not too many interests, or no interests at all here, so I didn't follow up too much.
Basically, you need three files for both 8112 and 8773, 2 os files for each version and the 0409 language file. And follow the instruction, it is quite simple.
I am on OEM, didn't unlock, didn't gold-c, no change other than forced update to 8107 then to 8112/8773. So I don't have tether, or anything that's working for gold-c on my phone.