Plug in the projector and turn it on.
The projector will have two arms, which will hold the reels of film. If they are not already out, take them out until they are in place.
Take the 8mm film reel, and place it on the front arm, or the arm closest to the projector's output. Place the empty film reel on the other arm, the one toward the rear of the machine.
Take the film, which should be wound around the front of the reel, and run it through a slot above the lens. If it is an automatically loading machine, it will do the rest of the work for you.
If the model does not load automatically, try and find the projector's original manual. Since models vary, the placement of the film may be different. For the most part, you will be running the film between several wheels before it is finally placed in a slot on the empty reel. The wheels will move the film through onto the empty reel which will catch the rest of the film as it is watched.
Set the control switch on your projector to forward projection. This makes the film spin forward.
Adjust the focus by using the knob around the projector's lens.
When done with the film, rewind the film by inserting the end of the film into the empty spool and flipping the knob to the backward projection position.