hello guys its XiPWNEDVYMASTERCHEIFiX and im gonna show you a little glitch some day you should have the challenge *light fare* if you complete this challenge you should get around 3000 or 2525. Play firefight and get 99 kills then end the game...then go back on it and get 1 more kill you should complete the challenge unplug your ethernet cable in the back of your xbox *QUIKLY* then plug it in again you should have the credits but still need one more kill to complete the challenge this is a quik and easy way to rank up thanks for reading *ILL POST MORE GLITCHES/CHEATS LATER* bye guys.:thumbsup*