First, you must apply for "permission" via the Mi Unlock tool. You sign into a Mi Account. You wait 360 hours (15 days). This is the "cooling period"—Xiaomi’s way of hoping you will forget your rebellious intentions. It is a psychological barrier disguised as a security feature. For the Mi 8 SE specifically, users often find that using the Xiaomi Community App (Version 5.3.31 or earlier) is the secret handshake; newer versions block the request.

When the Mi 8 SE reboots, the bootloader screen now shows an unlocked padlock icon. It is ugly. It is a warning. But it is yours .

But for those who persist—who short the test points, who downgrade the drivers, who type the incantations into a black terminal window—the reward is not just custom ROMs. It is the quiet satisfaction of hearing a digital lock click open, proving that with enough stubbornness, a machine will eventually obey its master.