This Guide might be Helpful for all Xperia device Users/Developers

1.First you need to download these 4 files
a)FTF extractor
b)META-INF folder and ROOTING files
c)7zip
d)Notepad++(Optional)

2.Extract ftf extractor anywhere you like

3.Open the *FTF file with 7Zip
You'll see these files and folders
Code:
META-INF
adsp.sin
amss.sin
amss_fs_urushi.sin
apps_log.sin
cache.sin
fota0.sin
fota1.sin
kernel.sin
loader.sin
system.sin
userdata.sin

4.Extract system.sin to the folder where you extraxt ftf-extractor.

5.Press SHIFT+RIGHT CLICK on the empty space of the folder.You'll see a dialog like this


6.select OPEN COMMAND WINDOW HERE

7.Type
Code:
aIUP.exe system.sin 4096 system

8.If this not work for you use 2048 or 8192 instead of 4096

9.You'll see
Code:
C:\ftf_extractor>aIUP.exe system.sin 4096 system
UnPacking system.sin to system ...
done.

C:\ftf_extractor>
Congratulation now you have extracted System from the ftf file

10.Now open the downloaded META-INF AND ROOT.zip
then,go to system and cut
Code:
app
xbin
bin
and pasteit in your extracted system folder (In step 9)
***Now your rom is rooted*****
OR
You can use Kitchen to ROOT YOUR ROM

11.Then Move your Rooted system folder to the META-INF ZIP
***Now you have made a flashable zip file****

13.(Optional)go to META-INF/com/google/android/updater-script and edit it with Notepad++