DISCLAIMER: XiPhone will not be held responsible for loss of data or damage to device whilst  following of this guide. Proceed at your own risk, and be sure to back your device up in advance.

With the formalities out of the way, let’s get started. Before you begin, make sure you’ve the following files at the ready:

Step 1: Download the AdyScorpiusMIUIv2.1-ICS-i9100-2.1.20.zip via this link. The file is over 100MB, so may take a few moments for those on slower connections.

Step 2: Once the download is complete, copy the .zip file to /sdcard.

Step 3: Boot your Galaxy SII into Recovery Mode.

Step 4: Select Wipe Data/Factory Reset, and then go to Mounts and Storage and select Wipe System.

Step 5: Install zip from sdcard – Version 2.1.

Step 6: Wipe Data/Factory Reset once more.

Step 7: Reboot your device, and you should be good to go.