1. If you have AutoHotkey installed, simply double-click MW2QS.ahk to run the script. Otherwise, run the MW2QS.exe file. Both versions duplicate the functions of each other, don't run them simultaneously! The plugin will continue to run in the background until manually closed (or system shutdown/reboot/logoff). To manually close the script: right-click the white-on-green "H" icon in the system tray and click "Exit".
2. Run ExternalHack (if you don't know how, follow supplied instructions).
3. Launch Modern Warfare 2 (don't forget to run it in windowed mode).
4. Toggle the QuickScope (default key is "alt+z") and, if required FoolProof (default key is "alt+x") features. To switch between different modes of QuickScope (full-auto and half-manual) press the toggle key several times. Each mode is indicated by specific "beep" sounds of different length and pitch.
Note: half-manual mode is blocked by default due to its incompatibility with automatic weapons and some killstreaks (e.g. Chopper Gunner). You can unblock it in "settings.ini" file.
5. Toggle (default key is "alt+c") the correct mode according to your current sniper rifle.
6. In full-auto mode press the aim button (right mouse button by default) once and get 1 frag, or if there are a lot of enemies you may hold it down and the shots will repeat as quick as possible. Half-manual mode requires you to zoom in by yourself and provides no auto-repeating.