ClockworkMod (CWM) Recovery is a legacy custom recovery specifically required for installing Android 4.4 KitKat-based ROMs
Conclusion
There are two primary ways to install this version depending on your current setup. Method 1: Flashing via PC (Odin) ClockworkMod (CWM) Recovery is a legacy custom recovery
CWM Recovery.ODIN.Compatibility Note: This recovery is strictly for the GT-I9100 model; attempting to flash it on the GT-I9100G or other variants may brick the device. Installation Guide (Zip Method) Download the CWM Recovery V6
2. Download the necessary files:
This guide provides the direct download link for CWM Recovery v6.0.4.5, specifically optimized for the Galaxy S2 GT-I9100, along with installation instructions. along with installation instructions.