Note: In 2017, all ROM images were removed on the official website. Huawei says it will provide a “more convenient and satisfactory update service”. Since then, all user must rely on over-the-air (OTA) updates. Reference

Finally 40 days after Huawai announced the EMUI 3.1 images for P7 in China on Oct 17, I found the official EMUI 3.1 image for P7-L10 in Huawei Germany Support(search “Smartphones” and “P7-L10”, and check the item “HUAWEI Sophia-L10 Firmware(Android5.1.1, EMUI3.1, C900B839, Europe)”.

Based on the official doc in the EMUI 3.1 image file, HUAWEI P7-L10C900B839 SD card Software Upgrade Guideline(For Service).doc:

If your phone is not in the scope, please check my previous article to get P7-L10V100R001C00B621(EMUI 3.0/Android 4.4.2) installed at first.

Downloaded it, uncompressed it, copied it to a MicroSD/TF card(better 4G or larger). After backup the data on the phone, use Settings->System Update->Local Update, the mobile will restart and use the image from MicroSD/TF card.

And it’s better to do a wipe after the upgrade. How to wipe:

• Shutdown the mobile
• Press “Volume Up” and “Power” at same time, in this mode, you can use “Volume Up” and “Volume Down” as “Up” and “Down”, “Power” as click.
• You will get a menu with three buttons, “Reboot Sytem”, “Wipe Data/Factory Reset” and “Wipe cache partition”.
• Choose “Wipe Data/Factory Reset” and click it
• Choose “Wipe cache partition” and click it
• Choose “Reboot Sytem” and click it

Then it should be EMUI 3.1(Android 5.1.1) now. Good luck!

Note:

• Version Number: P7-L10C900B839
• Custom Version: CUSTC432D001