Near the battery, just under the edge of the air cleaner there are a heap of connectors, I'd start there. They're really annoying to get at in mine because of the LPG conversion. I think they often just get cut off because they're hard to get at, but they need to be unplugged if anyone wants to use the box again.

There are other wires like the throttle position sensor, the full throttle switch, and the TCU, but I think the main ones to remove are the ones into the transmission itself (including it's rev sensor).

On the subject of removing wiring, do you want to sell your TCU?