If you're looking to remove a firmware update or revert to a previous version, or simply perform an OTA update on an Oppo A79 5G (CPH2557), here are some general steps:
If you legally own the device but forgot the MDM credentials: oppo a79 5g cph2557 mdm ota remove firmwareby link
Such firmware is — it is usually patched by third-party developers using tools like: If you're looking to remove a firmware update
: Create a full backup of the NV (Non-Volatile) data to preserve IMEI and radio frequency settings. oppo a79 5g cph2557 mdm ota remove firmwareby link