'85 Mondial Cab--Throttle cable replacement-How To?

Total cable assy replacement--- engine throttle body to the foot box/pedal. Can you help on the replacement procedure?-- Can I do this all from up top (maybe by just removing the center console and the interior firewall access panel) -- or do I have to get the car up in the air to gain access to the tunnel the cable runs through, from the bottom?

Thanks in advance,
Michael