Citizen makes a wide range of men's and women's watches and it is most renowned for the Citizen Quartz collection. Watches come with a standard factory warranty and repairs must be done by an authorized dealer during this time in order to prevent your warranty from lapsing. If the warranty expired, make minor repairs or change the battery by yourself. The large range of Citizen watches uses different mechanisms to seal watch cases. You will need to first inspect the watch case to see which method to use to open your watch back.

Work in a well-lit area. Ensure that your workspace is clean and free of dust or lint. Debris that gets into the watch mechanism may damage it irreparably.

Inspect your watch back. If there are screws holding the back in place, use your watch screwdriver to undo them. Turn the screws in a counterclockwise direction to remove, and keep them in a safe place.

Use the watch case knife for snap-off cases. If you see a small lip or indentation on one side of the watch back, slip the knife underneath and twist it to pop the back of the watch off. Take care not to damage the gasket if the watch is water resistant or waterproof.

Use a watch case opener if there are notches all the way around the edge of the watch back. Test the prongs to find the size that fits your watch case. Put the prongs into the case opener, and place the watch case opener onto the back of the watch. Turn the wheel on the case opener until the prongs are securely inserted into the notches. Turn the case opener in a counterclockwise direction until the back twists free.