Hi Netsuite Gurus

We need to delete a subsidiary off our vendors which was accidently csv uploaded onto them. The sub record we need to delete is not the primary, and shouldn't be on there. I have tried csv uploading with "override sublists" but that doesn't work. (CSV upload, vendor-subsidiary relationship, update, tick override sublist, map internal id, map subsidiary field then click pencil and change to [null]. then I get an error saying you need a subsidiary. But I really want to delete it out.

Is the only way to do it a script? (due to it being a secondary record inside the vendor record with it's own internal id?). I can't find this in Suite Answers.