Nevermind the fact that theres already about 20 threads in this subforum on exactly how to do the last boss, not to mention every other website with hints on this boss says exactly what puppychow said. Theres probably 4 other threads right on the main page of this subforum detailing exactly how to kill the boss.

If you have a tank you should be able to kill him at level 70. Its not difficult to avoid all of the bosses attacks, you just have to have something that shows his cast bar (which everyone should have by now, especially if you're playing any sort of tank). Without a tank I'm sure its much more difficult though.