(This is for beginners so don't whine saying it's an outdated game, these same steps apply to COD:Ghosts and COD:Black ops 1/2)
Okay, there are a few steps for this but the easiest and fastest thing to me is the interface. So, here's the tutorial:

Download link for Microsoft visual studio express 2012: www.microsoft.com/en-us/download/details.aspx

1.)Setting up the interface:
Start a new c# program and select: Visual C#/Windows form application

Start off by enlarging the program's interface by spreading the corner of the page.

once you've done that, you go to the bottom right of Microsoft Visual Studios 2012 and set up the following settings:


Now you can add a background picture(if you want) to make it look nicer and more "Personalized" I guess you could say.

Now setup your buttons:
2.) Adding the code:
Here's a pastebin of the codes you'll be needing to put: http://pastebin.com/ySiBneqY , and here's a picture of where to put them:

After you do that, you're going to add a reference to the code. The dll's that are needed will be found here: http://www.mediafire.com/download/33...3tmapi_net.dll http://www.mediafire.com/download/49...DotNetBar2.dll
Once you've added the dlls, you start adding the offsets for whichever game you are creating this tool for; This tutorial is used for creating MW3 RTM Tools, though, the same steps apply; but you'll be needing different dll files for each game. So, after you're done creating the RTM/RTE tool, you'll be able to compile this program and run it to see if it works. Note: I do not own a ps3 and am not responsible for your account being banned. You won't be automatically banned but you will most likely have to keep it on the low since this is editing whichever games' license agreement.

If this helps you, or you need more help or don't understand a step, feel free to pm me as i'm busy and won't be very active.