For me it took about 4.5 hours to do it. The thing about this quest is you must plan EVERYTHING, because the most part of the quest is in Ape Atoll, where there are dozens of monkey from level 79 to about 180 who range AND melee you, you have to sneak past them, so i suggest you learn the quest by heart, to be sure you won't die and have any difficults. and of course you need right equipment. It's a tough one. But as it's said, the rewards are great.