The steps for mutual repayment between credit cards are as follows:

1. Log in to the credit card bank website or APP, and select the function menu such as "Transfer and Remittance" or "Repayment Management".

2. Enter the other party’s credit card number and repayment amount, and select the payment method. You can usually choose to use your own credit card's available limit, debit card or third-party payment channels to pay.

3. After verifying that the information is correct, confirm the payment and enter the payment password or perform identity verification.

4. After the payment is successful, wait for the other party's credit card to receive the repayment. It usually takes a certain amount of time, 1-3 working days to arrive.