You do not need to restore factory settings to delete a Google account

Today, I want to change my mobile phone to a Google account, prompting me that there are otherProgramIf you cannot change the settings, You need to restore them to the factory settings (it seems that you cannot change the settings to the factory settings ); later, I found a method on the Internet that can delete the Google account without restoring the factory settings.

Delete the following files (Make sure that you back up your data to prevent unexpected events.). All accounts are deleted after the instance is shut down and restarted. It seems that some user data (voice and keyboard settings) is also deleted.
/Data/system/account. DB
/Data/system/registered_services/Android. Accounts. accountauthenticator. xml
/Data/system/registered_services/Android. content. syncadapter. xml
/Data/system/Sync/account. xml

 
PS: This method is risky. Remember to back up before using it. In addition, my mobile phone version is andorid 2.3, which has not been tried in other versions. This method is not guaranteed to be valid.