Hi there,
Your games will be available for you to download after reformatting, and you can do that from your direct2drive account page. You do not need to remove previous licenses, however if you run into any problems activating your software, please contact us and we'll be happy to help.
In the case you need further information regarding this concern please don't hesitate to let me know and I'll be ready to help you.
Regards,
Rich M.
Customer Support Specialist
Digital Distribution
So there, you don't need to remove previous licenses contrary to what the installation guide suggests. In this case, it sounds a bit like Steam!