[AT&T Samsung Galaxy S II Skyrocket SGH-I727] yval8957:
Well, I've been trying to work my way through this one, but I'm unable to find an answer. I tried to flash the UCLD2 firmware ICS leak on my SR and it didn't work, and now the phone goes on an endless boot loop. My phone was rooted with stock ROM (Gingerbread 2.3.6) and I had clockworkmod installed. I did a full back up with Titanium Backup as well. I saw a page in android authority detailing how to flash it using clockwork mod and followed the clockworkmod method:

Flashing via ClockworkMod Recovery

NOTE: You will be needing a rooted Samsung Galaxy S2 Skyrocket with ClockworkMod Recovery (CWM) installed. Check out our guide on how to root your Samsung Galaxy S2 skyrocket. You can also refer to this guide on how to root your phone running Android 4.0.3 UCALC4 firmware. For ClockworkMod Recovery, check this guide on how to flash ClockworkMod Touch Recovery to your phone.

Download the following to your computer:

Download the CWM-flashable UCLD2 package from here (skyrocket-ucld2-ics-leak.zip, md5sum: 5cb721bcacdadf7de2b0b9f041acc114).

Download the root fix file from here (su-bin-3.0.3.2-efghi-signed.zip, 164 kB).

Download the Facebook and Samsung keyboard fix here (UCLD2FontHotfix.zip, 226 kB).

Copy the skyrocket-ucld2-ics-leak.zip, su-bin-3.0.3.2-efghi-signed.zip, and UCLD2FontHotfix.zip to the root of your phone’s SD card.

Switch off your mobile phone.

Reboot your phone into ClockworkMod Recovery. To do that, press the Volume Up key, Volume Down key, and Power button simultaneously until Recovery Mode boots. NOTE: Once in Recovery Mode, use the Volume keys to navigate and Power button to select an option.

Perform a full wipe by doing the following:

Go to Wipe Data/Factory Reset and confirm the action on the next screen.

Select Wipe Cache Partition and confirm the action on the next screen.

From the main menu, select Advanced. From there, select Wipe Dalvik Cache and confirm the action on the next screen.

Go to Mounts and Storage and select Format /system on the next screen. Select Yes on the next screen to begin formatting your system.

Go back to the main menu and select Install ZIP from SD Card. Select Choose ZIP from SD Card and highlight the skyrocket-ucld2-ics-leak.zip. Confirm the action on the next screen to begin flashing the ZIP file to your phone.

Repeat step 6 but this time flash su-bin-3.0.3.2-efghi-signed.zip to your phone. You will meet an error message after flashing this file. Just ignore the error message.

NOTE: Ignore the error after flashing this file. Just go to Superuser and make an update after booting your phone.

Flash the UCLD2FontHotfix.zip file in the same manner as in step 6.

After installing the 3 files, go back to the main menu and select Advanced. From there, select Fix Permissions.

Go back to the main menu and select Reboot system now to restart your mobile phone.

Once your phone has rebooted into Normal Mode, launch the Superuser app and update the su binaries.

Congratulations! You have successfully updated your Samsung Galaxy S2 Skyrocket SGH-I727 to the leaked Android 4.0 Ice Cream Sandwich firmware UCLD2.

I did everything detailed in the clockworkmod method, was very careful and checked everything multiple times. Once I did those steps when I tried to reboot the system it goes on an endless boot loop. Sometimes it gets to the splash screen, sometimes it doesn't. No error messages are displayed, it just keeps booting. I am able to access clockworkmod, but I'm not sure what to do at this point. I've re-downloaded the three files listed in the article and I've redone all the steps, with the same results (obviously...). Not sure what my next step is at this point. Any help would be greatly appreciated.