Disclaimer: Modifying your device voids warranty (not that you have one) and carries risk of bricking. The author is not responsible for melted Kirin chips.
Unlocked Bootloader: This is the hardest step today, as Huawei stopped providing unlock codes. You may need to use third-party tools like DC-Unlocker.Custom Recovery (TWRP): You need a version of TWRP specifically compiled for the MT7-L09 or MT7-TL10 models.Battery Charge: Ensure you have at least 60% battery to prevent a shutdown during the flashing process. Step-by-Step Installation Guide huawei mate 7 custom rom repack