Put engine on TDC #1. Loosen the lock nut and then loosen the bolt on the underside of the tensioner a couple of turns. The internal plunger is spring loaded and will apply the correct tension to the chain. Tighten the bolt then tighten the lock nut. No the end does not get plugged. I would suggest you get a decent honda shop manual, all the info you need is in there and alot of information in there you will need for the other tuneup adjustments.