Update: This solution is only applicable for Xbox 360. Since you can't remove the title update on Xbox One.
Using cheats obviously takes away the skill needed to get certain achievements, however using them will make things slightly easier. Not everyone will want to do this but for those looking for an easier way out these cheats codes will help!
First you must remove the update from the game by going to the system settings, then to Memory and then hit Y where its lists the hardrives etc. Then Clear system Cache. This will remove the updates. Start up the game DON'T update and then when you are in the game enter the following:
Invincibility - hold LT and press A, RT, Y, RT, X, LB. If you entered the code correctly, you will hear a sound.
One shot kills - hold LT and press Y, A, Y, X, LB, B. If you entered the code correctly, you will hear a sound.
Display enemy health - hold LT and press X, B, A, LB, RT, Y. If you entered the code correctly, you will hear a sound.
I hope this helps !!!