It's a lot less intimidating than it looks, give it a shot before going for a guide. I'll warn you in advance though, expect to do some back-tracking, even when you know where to go it's unavoidable. And just about every elevator leads to a treasure chest, so if you take an elevator, you usually run into either a switch or a chest. There aren't many dead ends in there. And finally, before heading into the upstairs part of the dungeon make sure you have turned on all the elevators downstairs (you have to go outside twice on either side to activate them all). If you forget to do this you will do a lot more back-tracking than you need to, because if you don't turn on the elevators outside you will be unable to reach the 2 items that you need to activate the final central elevator that leads to the boss.
Last tip, not counting the 2 chests outside the temple itself, and counting the 2 key items you need to find to unlock the final elevator, there are 15 chests in the temple before you reach the boss. So if you don't find 15 chests, you have missed something. Good luck!