Can't delete Custom Google Search off mainsite.

Hi - I wanted this plugin for all my subsites, not my mainsite. A dev accidentally pasted the google script code into the Embed Code/Search ID on the mainsite. We are trying to delete the code, but it will not let us. Network disabled, and reinstalled, but every time it comes back the same way. It just turns pink if I try to save changes with the Embed Code/Search ID box empty.