you open it by inserting something small and pointy like a small flathead or steak knife at the opening where the light button is or next to the ir window.
then take another flathead and gently start moving down the side of the remote and you will see it start to unlock.
go gently and slide along the opening all the way around and it will open completely.
if there is something that looks like a small cap loose and there is a space marked c2 that is missing a cap then safe bet thats where it came from and you should replace it even if the remote seems to operate fine without it.
