Step 1: Tap the profile icon
(for iOS)
Step 2: Tap "Settings"
Step 3: Tap "Manage Payment Methods"
(for Android)
Step 2: Tap "Payment"
Step 3: Tap "Manage Payment Methods"
Step 4: Select the card you wish to remove
Step 5: Tap "Delete"
Step 6: Tap "Remove"
And you're done!