Just go to a parts store and get vacuum hose of the correct diameter. It might be english to metric so get what fits nice and snug. Gates is a good brand.

Or.

Get the needswings oil catch can. It comes with the hose.

The hose comes right off of that plastic t fitting. Be careful not to break t fitting removing hose. Not difficult at all. You don't have to replace other side if running fine. However I would inspect and replace any vacuum hose with cracks, deteriations, or loose fittings