How to Replace cotterless crank arms
This next video is going to show you how to remove and install square-spindled crank arms. The tools you'll be needing for this project include either an 8 mm allen key or 14 mm socket wrench, crank puller, 16mm open-end wrench and an adjustable wrench.
When removing it make sure to you don't scrape your knuckles on the chaining teeth. It's a very detailed video and should help with whatever you need. So good luck and enjoy!