Clutch 1st shows us how to do it on his Ducati Monster.
Chain adjustment is a regular part of motorcycle maintenance for anyone who has one. (People like me with shaft drive have it easy.) It's a pretty simple job to do on most motorcycles. What about some modern bikes with a single sided swingarm? You can't adjust bolts on either side, because there's only one side. The answer for most is to have a dealer do it. There is a better way, as Clutch 1st shows us on his Ducati Monster.
The Monster's rear hub includes an eccentric cam that can move the back wheel forward and backward slightly. This is how you adjust the tension on the chain. The key is a special chain tool that you can pick up for somewhere between $15 and $30. It looks very much like the tool you use to adjust a coil-over suspension system, and the theory is quite similar. There is an adjuster ring between the swingarm and the hub. After loosening two 14mm bolts on the hub, you can use this tool to turn this ring. This rotates the eccentric cam, which in turn moves the back wheel to tighten or loosen the chain. Tighten and torque the bolts afterward, and you're done.
This method is actually easier than adjusting a traditional swingarm. There is no risk of knocking the wheel out of alignment, causing the bike to roll down the road slightly sideways and causing excessive wear on the sprocket. Just dial the adjuster and it's guaranteed straight. Doing this yourself will also save you a ton of money. The tool is cheap, and the procedure is extremely simple. Who says Italian motorcycles are finicky and difficult to work on yourself?