Nissan Primera P11 144 ignition barrel

Ok, First, they aren't rivets, they're shear head bolts. Using a dremel you can cut a slot in the head and unscrew them, or you can tap it round using a hammer and thin metal chisel.

That said it's unlikely the ignition barrel is worn, more likely the key is. If the key looks worn then I would strongly suggest you get the key number from Nissan and get a locksmith to cut you a new key from the code. (No point copying the key you're copying the wear too.) Or get Nissan to cut you the blade. When you remove the horseshoe from the fob you will see a plastic piece in the old horseshoe, remove it carefully and transfer it to the new key blade, then reassemble the fob. Shouldn't cost too much as you aren't having the transponder chip replaced or the car re-coded. This will tell you if the key is worn (likely) or the barrel is (unlikely) and at least give you a decent starting point.



The key, if you insert a screwdriver into the slot and twist the fob will detach from the key horseshoe.



Horseshoe with transponder chip in place (The blue bit)



Key stripped. Be careful with the blue part, it's the most important bit of the key.