This box has three cables going in to it, one battery voltage, one ground, one control signal back to the controler. You can certainly open it, with nothing more than a screwdriver, but to reattach the wires you'll need a soldering iron, and a steady hand.
I had the same issue after crashing my bike last year, when the entire cable was ripped out of the box, I contacted Norman, and he told me :
"The loom should have a connector with black, blue and orange wires. These connect to v-, p, and v+ respectively on the hi lo switch."
The letters are marked on the circuit board inside the Hi/Lo box, the colours are those of the wires that the box connects to inside your front connection box, the colours of your loose cable may well be different, so you have to check inside the FCB, which connects to which.On my bike, it is:
V+ = Red
V- = Black
P = Green
But it's best to make sure, as I suppose it could vary from bike to bike.
Hope this helps.
Interesting that you say you're stuck in LOW, as I was stuck in HIGH, could you let me know which wire isn't attached or is shorted, as I never use the high setting, and so have thought about removing the box altogether, but know that unplugging it puts it into high.
