Parasta A-ryhmää, ei järjellä, ei taidolla, ei työllä, ei tuskalla vaan tuurilla! This is updated version of my original post. I have also included megafon modem.exe megafon modem Stick-mode firmware 21.
805 I’ve found and corrected some incorrect information on original post. Modern Huawei USB LTE modems can be used in two very different modes. Actually there’s also third mode which is subset of Stick, instead of native NCM interface it uses legacy PPP over emulated serial port. This can be sometimes useful with older routers with USB port but you won’t be able to reach full speed in this mode. Internet has plenty of information on how to do that. As it often is not all of that is true. Most interesting bits are also written in Russian.
Despite huge improvements in translations from Google Translate it’s still a bit of hit and miss. Which is also why some steps may seem bit pointless at first. You’ll need Windows PC for this. I’ve used 64-bit Windows 7 and Windows 10 PCs myself. Those are for older models like E3372s and won’t work with E3372h. Visit either one of these sites to calculate device specific “Flash code” based on your IMEI and write it down.