cut the chopstick top off....picture as show below
Step 4: Measure and tape
tape the chopstick 5mm shorter than the pen. as the last picture show below
Step 5: Wet the paper
wet the toilet paper and and roll it to a small pieces and put it in. put the first piece in and the second piece for shooting. when you push the chopstick, it will create high pressure inside the pen and pop the other piece off. watch the video for more action. any question, feel free to ask.