Theres a tool to hold the crank will removing the crank nut. The tools is about $60. The crank nut is torqued to something like 320 ft lbs... A long time ago I removed my crank pulley to replace the chain, etc... I used the tool and a breaker bar with a cheater bar on the end. The total length was about 7 ft. I could have used an impact gun but I didnt because mine couldnt fit between the rad and engine.