Reset AutoFill Data For a Specific Website

Step 1: Open the Safari preferences. (Cmd-,)



Step 2: Go to the "AutoFill" section.



Step 3: Click on the "Edit…" button next to the "Other forms" checkbox.



Step 5: Scroll through the list and find the offending website.



Step 6: Select the offending website and click on the "Remove" button.



Step 7: Click on the "Done" button to exit the window.



This should reset the text that AutoFill remembers for that site.