Replicate "Replace code that does nothing" effect in c++?

How do I replicate the "Replace code that does nothing" effect that's used in CE? I'm trying to make a nub console trainer in mw3, just got into hacking so I do not know a lot so please try to answer a simplified version. Don't bother replying how to do it if it's 'out of my leauge'. I only know the basics of c++ but instead of continuing onto sdl 2.0 I decided to do something that's more satisfying like hacking. For those intrestred here's some opcodes I found for mw3:

iw5mp.exe+27EB4 - nop - Bugged Rapid fire (Works best with pistols)
iw5mp.exe+2E992 - nop -Infinite ammo
iw5mp.exe+100DCE - nop -Godmode

Edit: Also if there's any good tutorial explaining basic game hacking in depth could you guys send me a link to it? I know the basics as I said but know almost nothing about Windows.h

NOP is an assembly instruction and stands for "no operation".
You can write a NOP to an address using pointers (if you have a dll that's injected) or using WriteProcessMemory. To do that, you have to write one or more bytes (depending on your case) to a specific address. You can write the number 0x90 to a specified address to NOP it. 0x90 stands for the NOP instruction.