For more information and a detailed walkthrough, including details on where to buy the filter check the following link convertyourcameratoinfrared.info
A Walk through step-by-step on how to convert your Nikon J1 to be able to film in infra-red.
Doing this modification will permanently alter your camera, rendering it unable to take 'normal' pictures. You can sometimes use a filter on the lens (depending on the camera) instead of permanently modifying it in this way, but this enables you to have much shorter exposure times, and doesn't require an external filter.
Disclaimer.
This modification will totally void your warrantee and if you break something, I am not responsible. The camera also contains a capacitor which may injure/kill you...again, it is at your own risk.
I am not affiliated with Nikon in any way shape or form, and they probably wouldn't endorse this,
The music in the video is Blue Danube by Johan Strauss, and is in the public domain. (Used from the youtube royalty free music library.)