How do I install my cartridge?

I recently bought a Denon DL-110 and a used Denon DP-300F that didn't come with a cartridge. I have no idea where to install the cartridge, and how to do it. The cartridge isn't coming out of the glass "thing" it's attached to....and I don't have a screwdriver. Do I need one?
Sorry if this is a stupid question, I'm just new at this, haha.