MW2 Tactical insertion glitch- tutorial

Ok, so once you get to level 45 you need to get 120 kills with one man army. (so you can get pro) After that set up a class with one man army pro, perk 2, steady aim. put steady aim because it may not look it but you are shooting from your hip. (you have to start out with a class that has tactical insertion. after that is done you want to click Y so you can see the classes you have. find a class that has throwing knife, tactical insertion, semtex, frag, c4, claymore. not blast sheild obviously. then press RB and A at the SAME time. DONT hold on. You should see a tactical insertion being planted then your equiptment will come out. NOTE: You cant sprint or it will go back to your gun.