You can change your payment method in your account settings.

For Google Play
  1. Open the Google Play Store app.
  2. Tap the Menu icon on the left side of the screen -> Payment methods
  3. To add a payment method, select the payment method you want to add under the Add payment method section.
  4. To edit or remove a payment method, go to More payment settings. You may be asked to sign in with your Google account.
- To edit a payment method, tap Edit under the payment method you want to edit.
- To remove a payment method, tap Remove under the payment method you want to remove, and then tap Remove.