locking wheel nut

[skatedemonuk]

Teeth on the nut key are getting very worn now and cannot get the rear wheel locking nuts off. any suggestions on how to remove these 2 stubborn bolts?
Also i am going to need some new lockings wheel nuts is there any i should get or will just any do?

Cheers

 

[Paddyhmfc]

My key broke the other month. Local garage couldnt get them off so went to Renault. £45 + Vat for all 4 and a few quid for normal nuts and the job is done.