After you have logged into the portal, on the top right corner, click on your profile icon and select Settings.
On this page, select the Plan & Billing option.
Select Edit your Plan. This will take you to your Delphi Subscription management page
Once on the Delphi subscription management page, select your active Delphi subscription.
Then choose Edit Subscription.
From the drop down menu, you can select the new subscription tier desired as well as the preferred term for the subscription. After making your selection, hit Update.