Hacking a bike lock is something that you may need to do sometime if you forget your combination or maybe just didn't bring the key for the lock with you. You should never hack a bike lock to steal anything and should know that this tutorial is for informational purposes only. The first thing you will need to do to accomplish this task is to get a marker. Once you have the correct size marker to fit into the key hole, just stick it in there. Once it is in the lock, just press down while turning at the same time. Doing this, should trick the lock into thinking that the marker is the key and the lock should come open. It may take a few tries but be persistent if you have to. Once again this tutorial should not be used to do anything illegal.