If you pry the shell open from the void of the extended 'key', you are safe from damaging the circuit board, but be careful after the shell starts to split open

So as you break off the key ring loop, try prying in both directions before it breaks off for good, you may pry apart the shell

On the 2nd one, the shell came apart without the knife when I was breaking off the metal key ring loop

I admit, I purchased the wrong shells

Not a hard plastic shell

Very good key shell