Guide to take apart the extruder?

I just got a used Gmax and seem to have a clog. I've been looking for instructions for how to disassemble the extruder but I'm not finding them anywhere. I can see a little piece of filament stuck underneath the extruder arm out of reach, but I'm not experienced enough with 3D printers to feel comfortable taking it all apart without any sort of guide to make sure I can put it back together correctly.

I have the extruder arm off, and I can see a piece of filament down there. The manual has a lot of details about the rest of the machine but just seems to say "the extruder comes assembled". Help please! I didn't have a problem taking apart the other one, but this is my first time with this one.