HOW to downgrade 4.2.2 JDQ39 back to ics?

[Fahad Jawed]

i recently updated my s3 which was on 4.1.2 rooted to 4.2.2 JDQ39. After updating it is unrooted. The main problem is the battery life, it looses 6-7% in just 2 miutes of stand by and this is fuc**** bull****. i just want to go back to ics or 4.1.1 :'( . i am a big android noob so idk much about android plzz help plzzzz.
Here's my phone details:
GT-i9300
4.2.2
Baseband version: I9300NELK2
Build version: JDQ39.I9300XXUFME3
Kernel version: 3.0.31-611730

Any help will be EXTREMELY Appreciated!!!

NOTE: if i first have to flash back custom rom to stock rom 4.1.2 to downgrade it to ics or 4.1.1 then how will i do that?? sorry friends idk much about android just help me with every possible step and downgrading link.
And umm btw i was looking at this page: How To Downgrade Samsung Galaxy S3 Jelly Bean To Ice Cream Sandwich (ICS) Stock Firmware - Vodeblog

IS it safe?? HELP!!!!!!!

 

[Putnoki Eutim]

hi i have same prob i have an galaxy s3 updated to official 4.2.2
https://www.youtube.com/watch?v=RZGPeuXIndQ
and i lose very mouch space and battery life 2
mn: i9300
bn: I9300XXUFME3
bv: i9300ceell1
i alredy tried to downgrade but then my phone even wont turn on i couldent get into recovery mode only in download mode so i aginst updated to 4.2.2 so i can turn it on but i want stock rom back
and i have a wierd map /storage/emulated/0 and it duplicates everithing and i have not so mouch space so...
somewhone said i should wait to android 4.3 update but i cant wait so mouch pls help!!!
and if i go to download mode it sais:
custom binary downloads : yes 2 counts
current binary:samsung official
system statusfficial
my phone is not rooted and not modified so i can update if 4.3 is comming
(srry for bad english)

 

[Putnoki Eutim]

you already got the answer how to get stock firmware back?

 

[GSDer]

What carrier are you with?

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