The vacuum hoses are the smallest rubber hoses, like 5mm diameter. There's a few of them running all over. For a few cents per foot at AutoZones, you can get a whole bunch of it.

Only take off one hose at a time, so you don't get confused where each one goes. Gasoline & coolant hoses have clamps on them, so just remove the ones that are only stuck onto their nipples.

The hose that actually connects to the valve cover has clamps, but it's only air. Other vacuum hoses are smaller. If you see any other hose that looks bad (cracked, rotted) take a picture & ask us...