You can not reset it. This can only the customer Support (but only when get the error that you have to many activations). For this contact customer support: https://forums.adobe.com/activity?streamSource=connections&streamID=4617539
Thank you for your reply.
Unfortunately I'm totally lost here. I can't find any way to contact support via your link. How does it work?
Choose Digital Edition.
Login and Adobe ID.
Click on the Blue Button.