Norcold is pretty good with providing installation and troubleshooting guides - you should be able to download. They are diabolical to find when it comes to mounting - possibly hidden under a panel or something - but usually simple to work with. The install guide will put it in nice pictures. It looks like that's an AC/DC model so it should be easier than a propane model.
Look for screws going into the sides of the fridge through the adjacent cabinetry... behind the driver's seat on the right side. The holes are probably covered with small plastic caps. I believe mine had two on each side. These side-wall screws were the only ones holding the fridge into the cabinet on my '03 EB50.