For Studio One 4 Users requesting an activation reset request, you can manage your own activations in your https://my.presonus.com account by clicking on the "My Products" link once logged into your account and then clicking the "Software" tab. Then click the link for the registered software you wish to change the activations for.
Once you have clicked on the registered software in your account, you will see a link to manage activations as illustrated below:
Click that button and a window will pop up that allows your to remove old activations to make room for new ones.
You do not need to contact support to do this. This is now entirely controlled by you the customer for each of your software licenses.
Note: If you don't see it change after removing activations, please refresh the web page to reset the cache.