Locked spare wheel cover issue

Hello, new Jimny owner here (I've introduced myself on the My Jimny section). I have just bought an '09 Jimny that has the chrome spare wheel cover on it, however I can't get if off. I've tried a ratchet strap and screwdiver to try and unlatch the locking mechanism but that hasn't worked. So I was wondering is there a "standard method" for dealing with this issue, or is it a case of drilling the lock out and trying to get a replacement barrel for it? Any advice much appreciated.