Piece of cake! Simply login, click on account, select "Account" to update your contact details and address, and "Billing" to update your card details or add a new card.
Log In > Account > Profile / Address / Billing
If you've added a new address, please check that the address your subscription is tied to is your preferred shipping address.
Account > Subscriptions > Bags Subscription / ShotPods Subscription > click on the drop down arrow > Update (shipping address)