Hello, Luke.
Welcome to Microsoft’s Community.
We understand that you want to merge two MCIDs to have all your information and achievements in one place, we will be happy to assist you.
To do so, we initiated a Private Message where you will be able to share in a safe way the required information to proceed accordingly.
To get this space, please find the link on the top right corner of this screen as shown in the image below:

We will be very attentive to your response, if no response is received, we will proceed to close and locked the case after two business days.
Wishing you a nice day,