Hi Michael,

A common request from Trailhead users is the ability to merge/transfer their Trailhead activity data (i.e. points and badges) from one account to another. The most common reason for this is when a learner changes companies and wants to move over the points and badges that they’ve earned against their old company account (or Developer Edition Org) to their new company account. 

Before We Begin: 
The following process assumes that the learner can still log into both the ‘from’ and ‘to’ Trailhead accounts. If the learner can no longer access the ‘from’ Trailhead account (e.g. they can no longer use their previous corporate login for Salesforce), we, unfortunately, cannot process the merge request.

One more thing (this time for realz): 
Please note that the process of transferring Trailhead points and badges from one account to another is irreversible. Once this transfer/merge happens, there is no way for the learner to reverse the process and move their Trailhead points/badges back to the original account.

What we need to initiate the merge process: 
In order to transfer/merge Trailhead accounts, we need 2 things:

 (1) The user id for the ‘from’ Trailhead account 
     
To get this information, do the following:

Login to the ‘from’ Trailhead account - the one you want to ‘give up’ and move points/badges from.

Click on the ‘My Trailhead Account’ link under your name. 
 
Copy the value after the ‘userId=xxxx’ portion of the URL. This is the ‘from’ user id. 
 
(2) The user id for the ‘to’ Trailhead account

Repeat the steps above to get the user id for the ‘to’ Trailhead account - the account that you want the points/badges transferred to. 

Requesting the account merge: 
Once you have the ‘from’ and ‘to’ user ids for your Trailhead account, please send an email to trailhead@salesforce.com with the ’Account merge’ subject line (mailto:trailhead@salesforce.com?subject=Account merge) and include the two id's. We will be in touch with you as soon as the merge process is complete.

Please mark this as best answer if the information helps.

Best Regards,
Nagendra.P