Back in the day, I purchased Music Maker Movie Score edition, and now I can´t download without using my old email, is there any way to migrate to my new email?
Since you need, essentially, to merge two existing accounts, I suspect only Support can help you with this since, if you attempt to change the account with the "old" address to use the "new" address, the system is unlikely to allow you to do this because it will "know" that the "new" address is already allocated to another account.
Use the Support button in the header of any forum page to contact Customer Support.