Put the KSMM.cfg file in to your Call of Duty 4 "main" folder and the z_sky_strike.iwd into the mod folder you record with (for example "ModWarfare").
When you've loaded up a demo type "/exec ksmm" to the console.

Here's a vid with this cfg used. Have fun!

http://www.wipido.com/video/63EdA4HfZHfh