Tutorial: Nikon Firmware Hack
Nikon Firmware Downloads: https://downloadcenter.nikonimglib.com/en/index.html
Firmware Hacker: http://simeonpilgrim.com/nikon-patch/nikon-patch.html
This is a really easy process... I'm literally going to list the steps.
1. Format your SD card in your Nikon camera.
2. Remove the card from the camera and plug it into your computer.
3. Use this link to download a firmware update for your camera.