Converting a camera in this manner is generally a pretty risky procedure, it's incredibly easy to screw something up big time and end up with a dead camera. I performed the modification on my D1x because 1) it's my spare camera, 2) it's older, and generally easier to get into, 3) I found a guide for how to take it apart. That guide can be found here.

I don't have a proper piece of IR glass to put in front of the sensor, so I ended up instead placing a piece of overexposed film.