Can anyone teach me how to upgrade FW1.0.2 to FW1.1.2 Please....Thanks

first you need to unstall oktoprep
than upgrade the iphone to 1.1.2

unlock the iphone with this pack: http://conceitedsoftware.com/iphone/1.1.2-jailbreak.zip

you need to install java.

open installer and add rep.frenchiphone.com to the sources.
install ANYSIM 1.2U and BSD subsystem.

switch the iphone to flight mode and turn the lock to never.

run anysim and afterwards install IWORLD and run it under your country.

thats it. good luck...