The Barnett's way and therefore technically "correct" way to do this is to put the bike in riding condition, remove the crankarm securing bolt or nut, then go out and ride gently around the neighborhood. Pay close attention to the arm as it will eventually wiggle itself off the spindle, hopefully. Sometimes more drastic measures must be taken. It has been my experience that a tie rod separator between the crankarm and bb shell can work - if you are careful. Good Luck,

-Ryan