You need the tool to remove them. You do not need a tool to install them. Simply install the link while the chain break is on the bottom, carefully rotate the pedals back until the link is at the top, double check to ensure the link is engaged on both sides then rotate the pedal forward while holding the rear wheel, to lock the link. Double check to ensure both sides are engaged. Yes, they recommend single use, but I have reused them if they still lock securely.