1. Backup data: Before brushing the machine, you need to back up the data on the device. You can use iTunes or iCloud for backup to avoid data loss.
2. Download firmware: download the corresponding iOS firmware from official website, and you can choose the corresponding model and version.
3. Connect the device: Connect the device to the computer through USB, and select the corresponding device in iTunes.
4. Restore the device: press and hold the Shift key (Windows) or the Option key (Mac), click the "Restore" button, and select the firmware file just downloaded.
5. Wait for completion: After the firmware recovery is completed, the device will automatically restart and perform activation configuration. When activating, you need to follow the device setup steps, enter a new ID, and then connect to the Internet to activate.
It should be noted that the brushing process needs to be cautious to avoid equipment damage or data loss. If you are not sure about the operation method, it is recommended to consult relevant professionals first.