How do you remove the interior panels to get at the factory speakers?

Depends. What year?

Arne, look at his name, its a ZX720

Chris

Is that a truck with the L6? Just guessing here.

If it's a 240Z, push the center pin all the way thru on the small buttons on each panel. Pull the button, gently pull the panels, then retrieve the button pins from inside the body (behind the panel)

Good luck.