Question: how to transfer money from one opal card to another?
Answer: Log in to your Opal account. You will need your Opal card account username and password.
Select the Opal card you wish to block and transfer its balance.
Select the 'Manage' tab.
Select 'Transfer balance of this Opal card'
Follow the prompts to transfer the balance to another Opal card that's linked to your account.