I'm pretty sure they meant the engine crankcase breather that sits on the valve cover and has an hose going to the intake.
It takes 4 bolts that for some reason are tight to 5000 ft lbs of torque and it's a Philips head. I've almost stripped the head of mine while trying to take the thing apart.
This is it. It's on a A1700 engine but yours should be similar if not the same.