How To Upgrade Baseband Without Locking Bootloader

[Redfoot]

Hi,
So now with the xiaomi.eu MIUI9 available, what's the procedure to upgrade the baseband?

I think I need to extract a file from the global MIUI9 official fastboot rom and execute a fastboot command to install only that file.

After that, I can then install the xiaomi.eu rom using twrp.

Can someone please provide steps?

Thanks!

 

[Redfoot]

I followed the info on this page to successfully upgrade the baseband version:
http://en.miui.com/thread-290568-1-1.html