No Asking/Begging for hacks.
Most, if not all hacks are patched on IW5M so no luck there. (No aimbots for it was released anyways.)
But get master131's Extreme Injector and it should be self-explainatory. Get a DLL. Add it to the list, set it to autoinject if you need to and use the process browser to select the executable you want to inject into. Auto-Injection will do as it implies thus no need to manually click the "Inject" button else you'll need to.