I want to change the side some doors are fitted on my early 1990s kitchen. The hinges easily unclip from the mounting brackets but the brackets are screwed into plastic plugs that sit in 10mm holes. The holes on the other side have no plugs. The plugs can't be levered out without damaging them but I've been unable to find replacements. Does anyone know what they're called, and/or where to find some? Thanks