I'm in the same boat. The best I can tell you have to remove the
boards from the back...
I don't know this printer but I do know that it has an "instant on" fuser, that
means that the hot roller is actually a sleeve that rotates around the heating
element.
It is nearly impossible to clean these sleeves, generally any marks they cause
on the paper are in fact due to wear and not due to toner buildup. My advice is
to look at the cost of a replacement fuser and compare that to the cost or an
equivalent printer.
Tony
MS MVP Printing/Imaging