You'll have to have a look and see how much damage has been done. Its not all on one plug (obviously) so sections can be chopped out.. However it all passes through 2 bungs in bulkhead, so if you only need to do a couple of sections, and leave the rest, you'll have to cut the plugs off to pass the wires thru the bung. (Leave tails on the plugs to I.d the colours and to splice bk onto). If it was me, and say loads of the engine loom (going thru 1 bung) was damaged I'd prob disconnect and replace everyting going through that bung- meaning you'll need all of it from a donor. if its only 1 or 2 circuits damaged either repair or replace just them