Replacing drum unit on copier: Sharp SF 2114

Question

I inherited the aforementioned copier.  It was fine for about 3,000 copies and then everything went black and the light for making copies went out.  I purchased a new drum unit, but can't figure out where it goes as it doesn't really look like anything inside the machine.  I can't find any instructions for replacing the drum unit online and nothing came with the unit when it arrived.  HELP!  I need to make copies and would hate to have wasted $170 on something that won't fit (or I can't make fit).