I'm removing an old fridge from the basement of my new (to me) house.
It's got a 1/4" copper water line to supply the icemaker. I have easy
access to the saddle valve that feeds the line.

What do I do to cut off the water supply to the icemaker line? Can I
screw the saddle valve all the way in or all the way out to shut off
the water? Or do I need to replace it with something else?

Thanks,
Michael