Migrating Windows 8.1 Local Accounts To Domain Accounts

I've decided to bite the bullet, and as part of my upgrade from WHS 2011 to WSE 2012 R2, to migrate client local accounts to domain accounts.

I understand the way to go is Windows Easy Transfer. I can't find much info on how this works, though. Why does it need to copy any files? Isn't it just a matter of changing SIDs on the client?

Also, it appears that Windows Easy Transfer has be deprecated in Windows 8.1 (InfoWorld). I have 3 machines in the house running Windows 8.1 – how does one transfer settings for those?

Thanks,

-jim.