When hunting migratory birds, Federal Law mandates the use of a magazine restriction device that allows only a total of three shells to be held in your shotgun.

Always keep the barrel pointed in a safe direction. Make certain that the shotgun is unloaded by checking the receiver, magazine and barrel. Remember that the plug (3-shot adapter) is under spring pressure so care must be taken for safe removal. Always point the end of the magazine away from your face in a safe direction.  Always wear eye protection when removing the adapter.

The magazine is spring loaded and can thrust out of the magazine tube when the friction-type magazine retainer is removed too quickly. Never look directly down into the cap end of the open magazine.

1. Make sure the firearm is unloaded and the safety is on before attempting to remove the adapter.
2. Remove the magazine cap. 
3. Place one hand over the retainer and pry it up with the other hand using a screwdriver. When the retainer releases you will feel the pressure of the friction ring and plug on the palm of your hand.  
4. Slowly raise your hand and let the magazine spring relax. Capture the parts in your hand as they spring out.
5. With the spring relaxed, the friction ring, plug, spring and follower can be removed. To reinstall, reverse.this procedure

Ranger Ladies/Youth models only: The Ranger Ladies/Youth 1300's are specially equipped with a segmented plug that can be cut to adjust the number of shells that can be loaded into the magazine. A full length plug with no segments removed turns this Model 1300 into a single shot when installed into the magazine.
As a new shooter becomes more experienced with his or her Model 1300, the first section of the plug can be cut off at the segment notch allowing one shell to be held in the magazine.
Eventually, with more experience, other notches can be removed to facilitate more shells in the chamber. When the entire plug is removed, four shells can be loaded into the magazine with one also in the chamber.