1- Backup your device using iTunes and make sure that your data (Photo – Contacts and Photos..etc ) have been saved on your PC, don’t let your iTunes backup your data automatically, the best way of backing up is by right click on your device from the left panel then click backup as the screenshot below if you don’t know the right way for backing up using iTunes or i Cloud check the link below.
iCloud- iTunes backup for iPod iPad and iPhone
2- Backup your Cydia packages, this step is for jailbroken devices only who are afraid of losing their installed Cydia packages (Apps – tweaks – themes). You have a lot of methods of backing up using Cydia store tweaks but you have to take care of the compatibilities of the tweak with your firmware, you can check the below link it will show a lot of methods of backing up the installed Cydia packages.
- How to backup installed Cydia apps, tweaks
3- Restore with iTunes the best way for restoring your i-device without errors is to restore by holding Shift + Restore for Windows OR holding the option key + Restore for Mac on iTunes then Choose the latest iOS firmware version
(Note: if you are hesitant about updating a new firmware its better to save your SHSH using the link posted HERE)
Note 1: Restoring i-device and updating to a new firmware will update the baseband so the unlockable users should take care and preserve their baseband before updating to a new iOS firmware the link posted HERE will help you to preserve your baseband on Mac & Window.
Note 2: unlockable users should check the the link posted HERE in order to use the best compatible tool with their device.
Note 3: You should take care of your iTunes version cause it may not be support to the firmware file version, also take care of Not having your internet access for iTunes to authorize the firmware restore
Note 4: You should connect your USB to the computer directly without using hub.
If you have a factory-unlocked iPhone, you don’t have to worry about preserving the baseband.
4-After restoring finished, iTunes will ask if you want to load your backup onto your device or “set up as new“. i think that its the important step, most of you load their backup onto their devices after restoring directly, if the restore is in order to fix issues so its better to “set up as new” then load your backup.
Note: Old backup may cause problems and issues cause of the bad settings so if you faced any issues after restoring its better to restore again an choose “set up as new” then sync your media and Apps.
5- The last step is the jailbreak and reinstalling the Cydia packages so if you tend to jailbreak your device on iOS 5.1.1 untethered check the links below:
Jailbreak 5.1.1 by Redsnow:
How To UnTethered Jailbreak 5.1.1 iPod Touch 3G, 4G Absinthe
How To UnTethered Jailbreak 5.1.1 iPad 3, 2, 1 Absinthe
How To UnTethered Jailbreak 5.1.1 iPhone 4S, 4, 3GS Absinthe
Jailbreak 5.1.1 by Rocky Racoon:(Convert Tethered To Untethered)