Method
Unplug the television's power cord.
While holding down both the "Confirm" button and the "Return" button on the Xiaomi Bluetooth remote control.
Turn on the TV, and when the "MI" appears on the screen, unplug the power cord.
(Make sure to unplug the power cord when MI occurs and immediately plug it back in.)
Wait for the system recovery mode to appear.
Once the TV has entered recovery mode, release the remote control buttons.
I found a method online for forcing a factory reset. Try it yourself.