If he has a gun (applies to handguns only), this is one way to do it but this video is useless if you don't simulate real world conditions during practice. 10,000 repetitions seem like a magic number to build a reliable reflex for this technique. 50,000 repetitions would seem like a good number to master this technique. However, please do remember that it's better to master just one technique than to know two dozen techniques you seldom practice. Simulating real world conditions (use a real gun, let your partner pull the gun on you as fast as he can since you have to calibrate the position of his hands, practice where your opponent is against the light, practice in a semi-dark environment, and so on) is always key.
[youtube]http://www.youtube.com/watch?v=ME3saoa1miI[/youtube]
For knife disarms, you have to master at least two techniques: one for the stabbing motion and another for the swinging motion. Few people swing their knives live Navy Seals so no need to practice complicated bullshit. The simpler the technique, the better. Again, simulating real world conditions is key. The rubber or plastic knife is good but nothing beats a real, sharp knife for practice. I couldn't find my two favorite techniques on YouTube so you'll have to choose any two techniques yourself.
For lead pipe or baseball disarms, a quick step forward Muay Thai clinch and knee to the groin is the most effective. You use the bone of your forearm to hit at the attacker's soft muscles (the bicep or forearm muscles) and then grab his nape while you raise your knee repeatedly to his groin and solar plexus. The key in this technique is the quick step forward to close the distance and render the weapon useless.
[youtube]http://www.youtube.com/watch?v=i8hbY8KXUiE[/youtube]
For hand-to-hand disarms, nothing beats the spectacular Jiujitsu arm bar if you want to lie down on the floor.
