[Huawei Mate 9 Guides, News, & Discussion] Oznes:
Noob, no programming background, just fiddler, first post, long thread, hats off to Mankind, Backbone and others. I thought I should post in case those having problems can glean something from my experience:

I followed the first post and found there are gaps I needed filled. Then on Page 3 there were more detailed instructions. I used them right to the letter. it didn't work.

I was on MHA-L09C316B180 and rebranded to MHA-L29C432B193 and then later to MHA-L09 8.0.0.362(C432), MHA-L29 8.0.0.362(C432) (last rom has two versions, I assume L29 went into my machine since I didn't rebrand from second to third rom.

Phone was bricked (can only enter recovery and fastboot) and unlocked and rooted.

Problem 1: The Update.bat, when clicked would open command prompt for a millisecond and close it.

Problem 2: I saw that a new update.bat by Backbone on this thread downloaded it and replaced the first one. The new one worked but the process failed to install TWRP saying it cannot find the file. I went to one of the HWOTA zip (the MHA) and found the recovery. I renamed it by removing MHA at the beginning of the file (so that it is reads "twrp-3.0.3-1-hi3660.img" and I pasted it on the following path (HWOTA_2017050101_Windows > HWOTA > Recovery). The last folder "recovery" was not there, I created it, opened it and pasted the file.

This solved the recovery installation (apologies if this has been explained before, the post can be deleted by mods).

Problem 3 : I could not find oeminfo. One of the HWOTA zip files had .bin files with OEM info. I have no clue how to get this info from here. I tried notepad and got gibberish. So I googled and found it online, downloaded it,and went to the TWRP folder on the phone SD card and replaced like for like and left the rest of the files as they were. Then when the time came I went to TWRP restored OEMinfo (deselect all the other options).

Problem 4: The process went well but didn't install the software. I repeated it various times and everytime it just didn't install the actual Nougat software.

Eventually, I went to the carbontesla with instruction to "download-install-huawei-mate-9-b193-nougat-update-europe-beta/" and followed their process. Most important is I downloaded the HWOTA from their link (which linked to Mankind ) but this time, it worked differently. I allowed me to enter options for rebrand or not. It worked like a charm. Unfortunately my phone ended up with SIM 1 and SIM 2. Sim 2 is greyed out but it is there, starring at me everytime I go to settings. This update.bat asks for the unlock code first and keeps it for the second unlock, very nifty.

Problem 5: Minor problem, the phone booted with "no network" (actually two off them one above the other). I removed the SIM tray and pushed it back in and it found the network (in case this happens to you).

With the new spirit, I downloaded Oreo and went through the same process, but didn't rebrand and it worked like a charm. I now have Oreo MHA-L09 8.0.0.362(C432). It says L09 but I still have dual SIM settings with the second greyed out. I think it's the OEMinfo that needs to be changed to fix this but I went through too much to try and fix that again. Phone works so why bother. I wonder if I can simply replace OEMinfo with L09 C432 and not do a new install. but that will be for another day.

I then did a soft reset via settings. Bootloader is locked, root access removed.

Observation: During HWOTA process, the phone reboots various times. Sometimes into recovery and sometimes into fastboot. In my case, everytime I connect the cable during these reboots, I could see both the SD card and internal storage on my computer and I could move files back and forth if I wanted. So for those who don't have SD card, perhaps you can start the process, then when the phone first reboots (after flashing recovery) you can transfer the zip files, do a full TWRP backup, then replace OEMinfo in the backup through simple windows drag and drop. and proceed with the process Not sure if this would work, but if you are stuck, worth a try. If if it's the first time you unlock, you may want to do a full TWRP backup first so that you have the OEMinfo files in the TWRP folder.