First off, I don't know really WHY you would want to skip this boss. I have seen some people have a lot of trouble though, and maybe they just want to skip it to get to the end. Maybe you also want to "solo" the instance at higher level but can't beat this boss - it will allow you to skip it.
I did this on my Warlock - when this boss resets, they disappear for a few seconds. If you cast your Eye of Kilrogg when you are just out of range, and get the caster guy to aggro on it, the boss will kill your Eye and then instantly reset (without aggroing you). This will cause them both to disappear for about 10 seconds - you can just run right past them!
I know you can do this on my lock (tested). You could probably do it with Eyes of the Beast and a well-timed Feign death on a hunter, or maybe even on a mage with ice block? Not sure if that drops aggro on you or not. I know for sure this can be done on my lock (did it twice tonight to freak my group out- they had a good laugh).
1) Be on a Warlock
2) Get close to bosses.
3) Cast eye of kilrogg, and aggro the caster boss with it (either boss is fine).
4) They will kill the eye and then reset and disappear.
5) You run past in the 10 seconds it takes them to repop!!