push in when you turn the key.

in an unlocked position the barrel of the lock should extend outward from the lock body, it is spring loaded to pop out when it is unlocked. you should be able to push in and turn the key and the barrel will stay inside the lock body, and lock you rack to the car. if his doesn't work, try visiting the texas kyak website. lots of knowledgeable folks their that will help you out . to lock the kyak to the roof rack. I would use a bike cable lock threaded thru one of the scupper holes and around the roof rack. tis should give you enough of a deterent to prevent theft.

have a good trip