If you click on the picture a new page will open with more info, a Q&A section.
Also take a look at the video.

Once you get it opened up check the rear rollers for bearing wean and if the rubber is out of round.
Since you have it opened up you may as well give it a bit of an overhaul.
So also check the belt, idler wheel, drum seals, internal air flow seals, front drum support bearing rings etc.
Then give the interior a good cleaning including the blower wheel.
This is also a good time to check/clean your vent system.