​An administrator can update a constituent's sustaining gift information by updating the sustaining gift itself on a constituent's record:
  1. Select Constituent 360 > Constituents
  2. Search for the constituent
  3. Click View next to the constituent's name
  4. Select the Transactions tab
  5. Under Sustaining Gifts, click on the pencil icon next to the appropriate recurring gift
  6. Under Billing Information, click the Enter New Credit Card button 
  7. Fill in Credit Card Number, Verification Code, and Expiration Date fields under the Billing Information section
  8. Click Update Billing Information button