Edit Data on a Form

Hi - what's the best way to find out how to edit the data for a form? Some of our forms are populating incorrectly (Assigned To) but I can't access the original sheet. When I go to "Manage Forms" for the sheet I want, this form doesn't populate.

This gets sent to me weekly from my manager, but the "Assigned To" names are all wrong. I'm trying to figure out how to delete those names and populate the correct names, or else, how to send the correct form.