If you're wondering how to take apart the key fob for a Nissan Primera, it's likely that you need to replace the key fob battery. This issue will come up from time to time because the batteries for remote keyless access have a limited lifespan: inevitably they will die. The good news is, it's simple to replace the battery. The only difficult part is separating the two halves of the key fob. Here's the trick: use a small, flathead screwdriver.
Insert a small, flathead screwdriver into the slot at the centre of the key fob, underneath the Nissan logo. If you have trouble finding the slot, look for it where the plastic part of the key meets the transmitter.
Gently pry down on the screwdriver until the transmitter separates from the key.
Insert the screwdriver into the outside edge of the transmitter to pry its two halves apart and obtain access to the battery.
To replace the battery in the key fob, use the screwdriver to pry up the old battery, then place the new battery facing the same way as the old one. Push the parts back together by hand until they snap into place. Check the remote operation.
Do not touch the circuits or battery terminal by hand. The key fob is water-resistant, but you should always immediately wipe any liquid away from it.