Just post what you need help with. Helping with everything would take atleast a week.

First off you need Dashlaunch, google therealmodscene and get a download. This enables your xbox to modify it's launch.ini to be edited to run plugins such as JRPC.xex. Once that is installed you will want to download plugins with some googling you can find Jrpc and RPC, RPC is the same as XRPC but newer. Tools to RTE will connect to these plugins and issue commands. Next, before you start using RTE tools you will need to get XDK, Xbox Neighborhood, this is needed along with visual studio full edition. To use mod menus for games such as mw2 make sure you are on the correct TU and replace the files in the game directory with the ones you have downloaded.