If you want. I wouldn't even bother disconnecting.

I was thinking about the cutting-through-the-cable bit, and shorting the
2 and 5 wires...

The procedure doesn't call for the shorting of the 2 and 5 wires. It doesn't
even call for them to be cut. If using screw terminals, they need careful
stripping. If using IDC, no need even for that. Even if accidentally cut,
there will be no problem with the line.

Christian.