My iPhone is OTB1.1.2 / BL4.6 / 04.02.13G / TurboSIM
I have tried different unlock methods discussed here but still cannot unlock, either stuck at "white apple logo" or "CFI Stage 2" in terminal....Now still in OTB112 TurboSIM, should I restore to 1.1.3 via iTunes? How to do this? Can anyone tell me the correct method (with steps) please?

Million Thanks!!