I teed into the coax just under the outlet, inside the cupboard, i have a 17.56-1.
I ran a second line through the floor, around the front step and back up behind the fridge.
I used the crimp on F connectors and coax splitter setup.
Just make sure you seal around the cable where you come in and out of the flooring.
Didn't take too long to do and works perfectly.