It's not TOO difficult, but it's refreshingly challenging compared to the rest of Twilight Princess. I've gone through it many times, and I almost made it through with only three hearts. (ALMOST. ...stupid Darknuts...)
You just need to make sure you bring fairies, maybe your bottle of fairy tears from Jovani if you saved it, potions, and the like. I never use Magic Armor, but it would probably be helpful if you had lots of money.
And then, if you still can't do it, there's a glitch on the Wii version that pretty much lets you skip all the battles if you put out the torches with the Gale Boomerang. And there's also the infinite bombs and arrows glitch if you tend to run out of those.
But, like I said, I do enjoy Cave of Ordeals and take it as a wonderful challenge. I'm in no way stating that it's easy. XD