How do I transfer a Visual Studio Subscription from one Azure account to another?

It's not easy.

1. Make a 2nd account at https://azure.microsoft.com/en-us/offers/ms-azr-0003p/ verifying your phone number and entering credit card information.
2. Go into the account you wish to transfer from at https://my.visualstudio.com and then click "Subscriptions" at the top nav. Finally click the "Add alternate account" link to associate the new account.
3. Microsoft is going to have to do the transfer for you if you don't see a "Change sign-in" link like I didn't. Call them at 1 (800) 642-7676.