You might do a search on this site and on Club Lexus. I have read before of the mechanism in the rear gate breaking, just don't remember exactly how they got in to fix it, but they did. Just search "inoperative rear hatch handle" or "broken rear hatch handle" or "can't get into rear hatch" or something along that line. Remember, if your 1st search words turn you up empty handed, try again. Search engines are pretty persnickity sometimes about how you word things, they're not forgiving like Google is.
The inoperative outside handle is probably related to the complete failure somehow. Bet next time you'll fix the original problem before it starts having babies, Huh?
Searched both this and Club Lexus about the issue and cant find anything about it when both are broke... Thanks anyway