You will need to log in to the Portal with your Redgate ID (this will be the email you used to register with). Once logged in, go to the license overview page and select the option to Manage license next to the license you want to change. You will need to remove yourself as a user and then invite the new user from that page.
The portal will also show trial licenses so if you are an assigned user on that license then you will see it in the portal.
Are you sure that a stand-alone license was purchased for SQL Source Control? Did your organization purchase a Tool bundle instead? If they did then SQL Source Control is likely part of that bundle.
For transferring SQL Source Control license to my colleague, if I remove myself from SQL Source Control license, will I be able to add another user? I don't want to cancel our license.
If you remove yourself from the license you will still be able to invite another user to the license as you are also an admin on that license. If you remove yourself and send the invite to the user, they will receive an email letting them know.
Answers
You will need to log in to the Portal with your Redgate ID (this will be the email you used to register with). Once logged in, go to the license overview page and select the option to Manage license next to the license you want to change. You will need to remove yourself as a user and then invite the new user from that page.
Please see this article for more on this:
Managing license users, owners & admins
The portal will also show trial licenses so if you are an assigned user on that license then you will see it in the portal.
Are you sure that a stand-alone license was purchased for SQL Source Control? Did your organization purchase a Tool bundle instead? If they did then SQL Source Control is likely part of that bundle.