How to upgrade my membership?

You can upgrade your membership by simply paying the difference between the membership types and you would receive the additional benefits.
If you have no transaction(s) left available to you based on your particular type of membership, you can get additional ones via an Upgrade: Guest to Classic, Classic to Premium, Premium to Platinum.
Go to your Dashboard, select My Account, then select Memberships. The upgrade tab will be displayed.  Choose your newly selected membership. Upon clicking the Register button, the payment difference that will be required is clearly displayed.