How to unlock and install Android 4.4/5.1 Lollipop into Xperia U ST25i (Working bootloader unlocking method) Tutorial How to unlock and install Android 4.4/5.1 Lollipop into Xperia U ST25i (Working bootloader unlocking method) Tutorial Reviewed by Maherr Live on Tuesday, June 02, 2015 Rating: 5