With a partner and in Forge mode, have a friend or yourself host a game. The person who is the host must be a player while the person who is not the host must play as the Monitor. Spawn a weapon like a Brute Shot and have the Monitor look as if he or she is going to pick it up. Do the same thing with the player. Do a countdown and have both players pick it up. On the Monitor's screen, the player's hands should have no weapon, but that player should see the weapon in their hand. While the Monitor is still holding onto the weapon, press RT and the player's arm should be ripped off, or press Y button to delete it. This may require a few attempts.