Please read all items in posts #1, #2 and #3 carefully and thoroughly as they should answer most of your update queries. Particularly post #3 as this has, "Tips for using this Dummies Guide".
This thread is only for the
Jelly Bean, (
JB),
Android 4.1.*, update for...
Samsung Galaxy SII, GT-i9100, GT-i9100M, GT-i9100P, GT-i9100T, GT-i9100G
#1.7. My CSC code is not eligible for JB yet but I want it now!
You do not have to wait for
JB to be released for your
CSC code. You can install, via PC software called
Odin, any of the released stock Samsung firmwares, for your model version, shown in post
#2.
Stock, official, Samsung Galaxy S2 firmware can be downloaded from the
SamMobile Firmware Page, after registering, by entering either "
i9100,
i9100G,
i900M,
i9100T,
i9100P" in the Search box on the page followed by your
CSC code, (
i9100***). To see all firmware releases for your model of phone, just omit the CSC code.
For step-by-step instructions on installing firmware via Odin, see
here. Ignore the
ICS file that they suggest you download and use the official
JB firmwares mentioned above.
This is for competent users and will void your warranty, if you have one, by flashing a firmware other than that intended for your original CSC code as well as negating future updates through Kies.