Join them to the domain
Login with their domain credentials, logout
Login as local administrator (not the old account, not the new one, a 3rd local admin)
Right click My Computer and select properties
Select advanced system settings
Go to the Advanced tab
Click settings under user profiles
Select their old profile you want and click Copy to
Browse to the location of their new profile and overwrite itIf the Copy button is grayed out then reboot and repeat steps two to nine.