Step 1, Download Oppo A37FW Stock Rom / OTA Update will not be responsible for any mistake and any damage that might occur to your device while performing the following operation. Install OTA Update Zip File Via Stock Recovery Maintain the battery charge percentage least 60%.Make sure you have a complete backup of your device.Download the suitable Stock Rom for your device.Read More – Increase RAM SIZE after root on Oppo?.we provide only Official Rom because all the glitches and bugs are debugged and you can get latest OTA update and install them If you need to upgrade your Oppo then you have to find upgraded Stock/Custom Rom/OTA – kitkat, Marshmallow, Nougat.