Firmware Update On Xiaomi Redmi S2 Hot! -

No PC, preserves data (dirty flash). Cons: May fail on newer MIUI versions; no more updates from XIAOMI.

If the OTA method is failing, showing errors, or if you want to downgrade your firmware version, using a Recovery ROM is the solution. A Recovery ROM is a .zip file that can be flashed via the stock recovery mode or the "Choose Update Package" option in settings. Firmware Update on XIAOMI Redmi S2