1. Pick a sturdy surface that I in a room where there are no lights. If there are windows, cover them. Set up your Lego scene and move the lights to light the scene.
2. Get your camera and set it up where you want it. Take the pictures as move your characters around.
3. Import all your pictures into an editing program. Put them in order and change the duration so that you achieve the right frame rate.
4. Export your movie and share.