I am about to change out the original speedo cable from my 68 coupe and noticed that it seems pretty difficult to remove from the firewall. My access to the firewall is obstructed by my Granade power booster and I have NO desire to remove the booster and MC for better access. Is there any recommended way to remove the cable? Cut it? How will the installation of the new cable be? Should I make a new hole in the Fire wall for the new one?