: In Settings > System > Developer options , enable USB debugging and OEM unlocking .
: Ensure all important files are backed up, as unlocking the bootloader performs a factory reset. Computer Tools ADB and Fastboot platform tools on your PC. Device Drivers how to root lenovo tb8505f top
Use the Lenovo Rescue and Smart Assistant (RSA) tool on your PC to download the official firmware for the TB-8505F. : In Settings > System > Developer options