Steps. 1  1. Open your iPhone's Settings. It's the app with grey gears that can be found on your Home screen. 2  2. Tap Safari. You'll have to scroll down to find this option. 3  3. Tap AutoFill. It's located under the sub-heading General.  4. Tap Saved Credit Cards. You may be prompted to enter your passcode or use your Touch ID 1  fingerprint. 5. Tap Edit.