Update Sony Xperia U ST25i to Official ICS 4.0.4 Firmware

Hello Everyone, I am totally new to Android and now i am using Sony Xperia U ST25i Gingerbread 2.3.7 … My current firmware is 6.0.B.3.188 I want update it to ICS 4.0.4 (Official) (Their is no sony update in my area with PC Comp.) My Sony Xperia U ST25i is

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