Log in to your
https://sphere.presonus.com account.
Go to Account and select Cancel Subscription.
You can go to
https://shop.presonus.com and purchase the upgrade for Studio One 4 Pro to Studio One Pro 5.
After the purchase the perpetual license will appear in your account.
In Studio One 5 that you had installed with Sphere, open up Studio One Activation on the menu bar and click the down arrow to select option to Show All Keys, then select your Studio One 5 Pro license and click Activate. Then you're all set.
If you're not sure, contact support at
https://support.presonus.com so a dedicated support tech can assist.