Managing personal Outlook.com account settings, security, and privacy
Greetings!
This is Tin, looks like you would like to transfer your MS Office 365 subscription to your new MS Account. I'm afraid that there's no way to transfer a subscription directly. The option is to cancel your current subscription and then subscribe again using your new MS Account. To do cancel, you may sign in to https://account.microsoft.com/services and you will see an option to cancel from there.
Then please feel free to purchase MS Office subscription from MS Store anytime using the new MS Account.
https://www.microsoft.com/en-us/microsoft-365/buy/compare-all-microsoft-365-products
Thanks,
Tin