Changing locks on r-reg micra?

I have standard keys (not central locking) on my micra.
I know they have some kind of very basic NATS system as it says NATS on the key I have and there is a flashing dash light.
After loaning my car and the 'good' key to someone because the one I used was fairly knackered (was driven on by a tractor) they managed to snap it. The worse for wear key is now near death and the door barely opens so I will have to go for a new set. Half the old key is in the passenger door lock so needs replacing too.
If I go to the 'scrappy' and get new keys and locks, will it be a simple swap over or will I need to do something special with the NATs?