Usually Huawei Flash Tool or E_Firmware_Flasher . Step-by-Step Guide to Using the USB Loader
Before flashing any files, you must verify your exact device model. Using a loader meant for a different variant will permanently brick your router. Specification Huawei Mobile Wi-Fi Model Number E5577cs-603 Chipset HiSilicon Balong Supported Bands LTE FDD B1/B3/B7/B8/B20, TDD B40 Connection Interface Prerequisites and Required Tools usbloader e5577cs603 portable