To edit your shipping address:
Go to the account page
Enter your registered email address - this is the email you used when creating your subscription
Click Continue
You'll receive a one-time verification code via email
Enter the code on the login screen
Select Subscriptions at the top of the page
Select the Edit button next to your shipping information
To edit your billing address:
Go to the account page
Enter your registered email address - this is the email you used when creating your subscription
Click Continue
You'll receive a one-time verification code via email
Enter the code on the login screen
Select the Edit button next to Billing