Unhappy Pl help me updating y S3 from 4.0.4 to 4.1.1

I m using DoCoMo SC-06D in japan i.e. Galaxy S3 elsewhere.... my problem is that I wanna unlock it but for that I need to have 4.1.1 install on my mobile but it has 4.0.4 ... if I update it simply from device , it will take me to the latest available update but I wanna just update it to 4.1.1 only.... is there anyay I can choose to update it to 4.1.1 version only and not later than that. pl helpme... I need to o tht urgent...