Have not tried it but can give you info on doing it...You will need a few supplies.Soldering iron,solder,heat shrink tubing(a few sizes),a heat gun,and a bottle of liquid paint-on electrical tape.
Cut the cable in two at damaged spot.
Strip back 3" of the outer insulation from both sides of cable.Use sharp utility knife or straight razor blade.
Strip 3/8" from each conductor on each side.Twist conductor ends leaving them straight.
Use soldering iron and solder to tin ends of conductors on both sides.
Install 6" heat shrink over cable and slide out of way.Install a 3/4" piece of shrink over a conductor and slide as far as possible.
Use iron under both ends of same conductor and solder together side by side/end to end(Parallel each other).Slide down shrink and shrink with gun.
Do the same on the rest of conductors.
Slide outer shrink over splice.Use gun to shrink.
Seal with several coats of liquid tape.
Likely this will work but your only snag would be a possible loss of shielding for noise suppression.That would either be a braid or foil under outer insulation.
I am willing to aid you in any way.Let me know