I know you found your answer since you posted the support phone number. I deleted that post, since the number is only available to paid subscribers and the forum is public.
As I trust you discovered, a subscription can't be transferred, but you can contact support to cancel the existing subscription and then start a new one with a new LiveID. Note that this isn't needed, though, as the LiveID does not have to have an active Hotmail account or even an email account associated with it - it is still valid as a LiveID. You can't cancel a LiveID as long as there are active subscriptions (for any paid service) associated with it.
-steve