Hi folks,ayam trying to root my friend's S2 i900G using the first method but system failed to push the files into the S2 i900G - the phone boot normally though but still unroot.
Baseband is I9100GDXLS2.
Build Number is JZO54.I900GDXLS8.

First try - i was trying to flash the SU-BB-Installer.zip in stock recovery mode but also failed due to signature not verified.

Any help - thanks.