SKSguy,
I've built a G3 from a kit, and I think all you have to do is take a pin punch and punch out the sling attachment (from the other side). Take the end cap off the cocking tube, and the sight should be free. Of course, you'll need to get that flash suppressor off, too. Good luck!
I think you should be able to get an exploded view of the G3 by searching online. Even the HK site I think has owner's manuals that are in .pdf format.
Remember, I am not a gunsmith, but my G3 does fire!