kaskais that image of: after the alternator is removed and are they chain tensioners.
I have a chain rattle, and maybe I can replace those tensioners?

 

Yes the alternator is removed on this picture.
All the pics from job are there http://www.zone.ee/kaspar10/CBR/index.htm
You can see removed alternator http://www.zone.ee/kaspar10/CBR/pages/IMG_6309.htm
There you can see the dumper itself http://www.zone.ee/kaspar10/CBR/pages/IMG_6288.htm is also taken out from engine.
And chain is fixed with wire http://www.zone.ee/kaspar10/CBR/pages/IMG_6281.htm

Now about changing the chain tensioners - If you have VERY good fingers it MAY be doable, but there is really not so much room and the tensioners are pretty big[&:]. So i would suggest to open the engine for this job.
But first you should make sure that the rattling noise is not coming from cam chain. The cam chain tensioner is place where hurricanes make noise usually. and the cam chain tensioner is much easier to replace - again with engine in frame and most fairings on.