Q:
Where does the vibrator go in this once it's made? (inside, bottom, top?) Is the vibrator accessible once the rubber has set, and can the battery be replaced?
A:
The instructions state the following:
"when you're ready, completely pour the combined contents of both jars of rubber mix into the mold. Next, position the vibe in the center of the filled mold and let it all set."
The vibrator would go into the open end and I believe you would have access to change the battery.