Just to add to it the cam chain tensioner has a spring pulling on it and a head that's kind of the opposite of what people think it should look like so it can't unscrew anyway. And if it does something will break so scuff and dab RTV on it and call it good till you need to take things apart.
Many here have done that and as long as you're in there replace every gasket, oring, any problem area and you won't have to worry about it next time.
This is why the cover has to be removed. Note the flange on the bolt that won't fit through the hole in the rear cover.
I've seen dire warnings a number of times never to loosen the adjuster bolt mare than 1.5 to 2 turns or it falls out and the tensioner components fall apart.
In actual fact you should unwind the bolt at least 3 turns as the bolt imprints into the tensioner body if overtightened. If you don't wind the bolt clear of these indents you may have made the adjustment without the tensioner actually having moved.