I think they mean the final gear at the back wheel or some refer to it as the diff, yes you need to remove, thats just the 4 nuts on the flange to the "diff" and off she comes.
then you can remove the splined shaft inside the swingarm, it will give a little bit of resistance, try levering it out with a couple of flat blade screw drivers.
from here you should be able to remove the swingarm, leaving the uni joint attached to the middle gear.
alternatively you can pull back the bellowed rubber cover, undo the 4 uni joint nuts n bolts and remove uni, splined shaft and swingarm as one.