OK...I am 83 years of age. I am a Mechanical Engineer (retired, of course); I have a Master's Degree. I could not figure out how to upgrade the firmware. It appeared to me I was to download the firmware to a newly formatted memory card, then put the card in the camera and update the firmware. I did not know until I reverted to Youtube and watched a Fuji Representative show me how to do it that the "bell in my brain" rang. Once I found out that first you down load the update (and nothing told me it was down loading) to my PC, and then copy it to the memory card, was I able to do it. I use a PC with Windows 10, and by default downloads go to a folder called "DOWNLOADS" (what else?). Fortunately the Fuji rep also warned that if I had downloaded the file more than once, the PC would give them new names, adding (1), (2), etc. Sure enough, since I did not know what I was doing, I down loaded the upgrade file 8 times and the PC gave them all different names. I deleted the newly named files and only copied the original file to the memory card. That was another question I had: where on the card should I install it? I "dragged and dropped" the upgrade file directly on the memory card icon, and it worked. So now I have my GFX 50R running the latest firmware. If I ever have to do another firmware upgrade, it will not be a problem, but it seams each camera maker has their own method of upgrading. I also use Sony (A7RIV) and came from Nikon and Canon.
I am embarrassed, but maybe my trial and error may help someone out there. Stay safe.
Dave in NJ