A Collection of Firmware for your Modem
These are links to an external site that contains firmware for various different modems. You can download these and flash your modem to a new revision of firmware. Be sure that the firmware you choose matches the firmware being used on the modem. There are slightly different versions of firmware for the same modem.
There is also a link to a PDF that explains how to use the QFirehose program builtin to ROOter to flash Quectel modems.