How to disable the device managed by the Administrator and re

Hello,

You cannot disable the administrator on an Android smartphone. You need to know the password or the sequence to access the main screen.

You can reset the device, which will erase all data and restore it to factory settings.

See:

https://fr.wikihow.com/reset-an-Android-tablet

and;

https://www.commentcamarche.net/infos/25887-ccm-and-the-unlocking-of-phones/