The second method which even deletes Cydia along with Yalu is by erasing the device using i Cloud.
Step 1: Create a backup of your device either using i Tunes or i Cloud so that you don’t lose anything in case something bad happens to the device during the process.
All i Phone or i Pod Touch settings are restored to their factory condition. First thing to check is to make sure you have the latest version of i Tunes installed on your Mac or Windows PC. When your phone is detected, select it in i Tunes under the list of devices.
If your i Phone is not responsive and i Tunes does not detect it we must put your phone in DFU mode.
Step 5: Open Find i Phone and enter your Apple ID’s password again.
Step 6: Go to All Devices and select the device you want to erase.
This method, however, doesn’t erase the every piece of the jailbreak.
In order to get rid of every byte of third-party software, you’ll have to either restore the fresh stock i OS firmware on your device or erase everything on the already installed firmware.If you restore the fresh firmware using the i Tunes method, you won’t be able to re-jailbreak your phone until the developer releases the updated version of Yalu.The safest and the simplest method of removing Yalu is to erase your device without restoring it. Maybe you jailbroke it and things did not go as well as you planned?Perhaps you have to take your i Phone back to an Apple Store because of a hardware related issue and you are jailbroken?Well I will tell you how to restore you i Phone back to it's factory settings in a few simple steps.