If it's like the 650 it's held in by a pressed-in stud, with a washer under the head. I managed to get mine out by tapping a thin bladed screwdriver under the washer and carefully levering the stud out.
It was a while ago, but I think you need to operate the lock for it to pull out the slot it's in (it doesn't just fall out). With a new one you'll obviously have a key so that's OK. With the old one you drill a hole down the centre of the lock, until it all disintegrates, and then it WILL just fall out.
As they say "installation is the reverse of the above"
Phil