You can up- or downgrade your membership easily in your account settings. Here's how it's done:

  1. Log in to your Subba-profile
  2. Head over to My Account 
  3. Click the 'up- or downgrade' button
  4. Select the membership you would like

You will switch automatically to the new membership on the end-date of your current membership.

 

Heads up: Up- or downgrading is not possible when your payment is being processed.