From everything I read when I was looking into it, it's not doable by anyone other than the dealer.
I think if you're doing a MIB1 -> MIB2 conversion and go with a box hacked to remove component protection, then it can be enabled unofficially, but I don't think it's possible otherwise.
I wonder at this stage if dealers wouldn't be willing to do some sort of a deal on it. I got it thrown in when I bought mine used this year and it didn't take much persuading, so it might be worth having a chat and trying to work something out.