You can access the My Subscription window from the switcher. 

Billing information
You can switch tabs from My Subscription to Addresses.
Click on 
Edit next to Billing Information to edit the following details
- Tax ID
- Billing name
- Billing email
- Billing company
- Billing address

Click on 
Update to save your changes

You can edit your Shipping address from the widget below.

Credit card
You can find your current credit card details and the option to edit it on the My Subscription Page
Click on 
Update/ Edit.

Enter your new credit card information and 
Update Payment method