Upgrade process from Membership Lite to Membership PRO

Hi Team,

Yesterday I have purchased 3 month Membership PRO, before that I have been using Membership Lite module and did some of the customization.

Now, how i can use membership LITE module as a PRO version. Also I want to create more subscriptions levels, how I can acheive by using membership LITE version module. Also where I have to use the activation key provided in my account in Membership LITE module for the upgrade purpose.

Please advise us at the earliest.