If you're looking to break a puck lock, there are a few things you can try. The first is to use a hammer or other heavy object to strike the end of the shackle. This will hopefully loosen the locking mechanism and allow you to pull it apart. If this doesn't work, you can also try heating up the shackle with a blow torch or other heat source. This will expand the metal and hopefully allow you to pull it apart. Finally, if all else fails, you can always saw through the shackle with a hacksaw or other cutting tool.