Pass-Through Hole and Gromet at back of cab

There are holes through the firewall and at the back of the cab. These are plugged by round rubber gromets.

I'd like to use the back-of-cab hole to run antenna wires through, but I have no idea how to access the hole from inside the cab.

The hole is between the little cargo space under the back jump seats.

My last Taco (99) didn;t have the plastic "liner" in the cargo space. My new (08) does. I couldn't figure out how to get to the hole through the plastic liner of the cargo space.

Does anyone know how to access this frpom the inside?

 

I think unscrewing the cargo liner will provide access to the gromet hole.
I'll try to do that when I have some time...

 

The cargo trays come out pretty easily. I think there are three screws on the large one and two on the smaller one.