I could really use some guidance with an OG related task. I'm needing to modify a form used to add existing users to organic groups. The path is "/group/node/1/admin/people/add-user". I need to remove the user search box and instead implement a couple of name searches: "Firstname, Lastname", and "Lastname, Firstname". Not sure what I should be modifying via a hook_form_alter, or other hook. Any thoughts?
Attached is a before and after view of the form. I appreciate any guidance anyone can provide.