The loom comes in two halves:
1: the car electronics side
2: the engine.

You should only need to remove the engine loom, this is located down the driverside of the Cavalier, with the ECU bolting to the inner of the bulkhead.

Just mark up/photograph the wiring plugs/connections when you remove them from the engine. Then remove the engine loom.
You should be left with a smaler section of loom and wont have the alarm ecu, 4wd ecu or anything of that nature.

hope that helps??