You would have to open up the harness and wrap the wires inside the plastic fluting, then put the fluting back on, then tape it up again.
The issue is the fluting rubs little grooves through the individual wires' insulation (the colored parts) and exposes the metal wire strands inside. This both thins and weakens the wires, and also exposes them to short circuits between each other.
Most of the problem happens in a ~1 foot section as the harness passes by the starter, but there can also be issues where it bends around the head under the injector harness plug as well as where it turns and goes up behind the tandem pump area and across the back of the valve cover.
Plus, as I have found, sometimes I just cannot pinpoint *exactly* where in the harness a problem lies, but the problem IS remedied once a new harness is installed.
What sucks is, they are obsoleting some of these BRM harnesses now, so cobbled fixes may be the only choice we have going forward, which really, really sucks. Time = money. If you are doing this yourself, you can assign whatever amount you want to your time, but when you are paying someone else to do it, paying them 3+ hours labor to try and fix a harness will be more than the cost of a new harness provided it is still available.
A4 Jetta trunk harnesses, another common problem, are also NLA. I have sadly had to spend FAR more time rebuilding those than a new one would have cost, and there are still a LOT of those cars on the road. I wish someone in the aftermarket would step in and make a replacement available. But a BRM engine harness is far more specific, and not likely to be something anyone will bother to tool up to produce.
