ROM switching :
There are guide already available on stock ROM thread, but here i am showing how to switch ROM and How to update ROM in day to day with keeping Root and data intact. Hope this can be great help for newbies.
There are lots of inquiries around regarding switching ROM. Here I have attached graphical representation, which can be helpful to decide your way to go.
Here I have divided guide in 4 parts
B.Flashing Pre rooted ROM
C.Switch ROM using Mobile Odin Pro
A.Backup Data :
If you have non rooted device then you have limited option for this.Mybackup Pro also have some option for non root user too.
If you have rooted device then it will be at great help for you. Commonly used application is Titanium Backup and Mybackup Pro
In sort Titanium is feature rich, Mybackup is easy to use. I will discuss TB here in detail
What to backup first time?
when using first time, this option is good - 'Backup all user all + syst data' This will takes backup of all System data like contacts,SMS,call logs etc as well it includes all the applications you have installed along with data e.g. levels of game, app requires credential (you have to select app+data option while backup) - See image below
After this you can ad schedule for day to day auto backup. see image below i have scheduled it to take backup of system data once in a wk while any application i will install, that will be backup 5 days a wk. But this is highly configurable and you can set it according your needs.
Now lets starts with switching to Stock GB ROM from any ROM you have installed.
B.Flashing Pre rooted ROM
Starting from Any ROM you are having, if you want to move to stock rooted GB ROM then easiest way is to Flash pre rooted ROM
How to ?
1.Download This ROM
2.Extract file and Flash using PC odin.
File and tab selection is shown in image below PS :File name in PDA tab will be different,here is demonstration purpose)
If you can't see image above, click This
After successfull flashing device will be rebooted, and you may experience Force closed OR stuck at samsung logo. This is normal perticularly you are switching from custom/ICS ROM
Reboot device in recovery and wipe cache and wipe data.
You will have stock GB ROM + Root + CWM at end.
From here you can flash any custom ROMs require base ROM GB. using recovery.
OK Now next step
Switching from Rooted stock GB ROM / Rooted ICS ROM to another Stock GB/Stock ICS ROM with keeping Root intact.
Here you needs Mobile Odin Pro.
How to :
C.Switching ROM using Mobile Odin Pro
1.Download desired stock ROM from here and extract to .tar
2.Download custom kernel in .tar (odin version) according to your selected ROM. Here is kernel repository by chasmodo worth to look.
3.Copy above ROM and kernel files to Int SD card(recommend internal, but you can use Ext SD too)
4.Install Mobile Odin Pro, and open. (if you opening it first time, it will ask to doenload flasher file of abt 8MB)
PS:Here below image is diagramatic representation of flashung LRG ROM + Notecore kernel
5. select 'Open file' (see image)
6.Point to ROM file which you have copied to SD card
7.It will popup and all field will be filled automatically
8.Select Kernel tab and point to custom kernel file you have copied to SD card (see image)
9.tick 'Enable ever root' and 'Inject superuser(super SU) -(see image)
10. Flash firmware
Device will reboot in recovery and flash ROM, and of successful flashing it will reboot normally
11.Reboot in recovery
Wipe cache, wipe delvic cache and wipe data
Now your device is updated to your desired ROM + Root + Custom Kernel with advanced recovery.
D.Restore data :
-Add google a/c to newly flashed device and download Titanium backup
-Avoid system junk to restore(red colored), you can restore call logs/SMS
-select this option to restore 'Restore missing app + data'
-In next screen of list of missing application, look for any application you dont need, as well untick any application listed, which was a part of system application of previous ROM
-It will finish restoring of you app with data
Reboot after finish
And you are ready to play with device with New ROM.
Hope this will help newbies ........................
and Happy Flashing.