How to clean up the information thoroughly before selling iphone?

Before the iphone completely cleans up the data, you need to turn off the function of finding my iphone, and then choose to erase all data and content in the general recovery interface. Details are as follows:

1. Click Find My iphone in the setting icloud interface to enter, as shown below.

2. Turn off the "Find My iphone" switch, as shown in the figure below.

3. Does the system need apples? ID verification, enter the password and click Close, as shown in the figure below.

4. Then enter Settings-General, as shown in the figure below.

5. In the general interface, pull to the bottom and click Restore, as shown in the figure below.

6. Click Erase all data and contents in the recovery interface, and enter the verification password according to the prompt, as shown in the figure below.