Funny u should mention it, but i had a problem taking the crank shaft pulley off myself. Basically, you have to keep the crank shaft pulley from moving around, either with a tool or taking the flywheel cover off and sticking a screw driver in the teeth of the flywheel and having someone try bust the nut (no pun intended) off with a breaker bar or impact wrench.
If the nut has never been broken before, it might be hard to. I used a breaker bar and an impact and the friggin thing did not budge. I had to take my car to a friend who had access to a 4 foot breaker bar which finally broke the nut.