Giving your old gps new life

Need some help here. I have 3 old Garmin Nuvis for which map support stopped around 2012 - 2014.

I know this can be done and knew someone who from time to time updated maps for me in the past, but we lost contact.

So I googled a bit and found this Youtube video of someone explaining what you need and how to do it, but the guy talks fast and skips over steps I actually need (obviously regarding them as run of the mill computer proficiency)

The latest map sets you get from a site called Openmapchest.

Then you need some program called Qbittorrent to download it correctly/in the correct format or something.

I was able to download and install the Qbittorrent program, and it looks like I have the new map on it. But I don’t know how to proceed from there.

It appears you have to extract the files through Winrar or Winzip and then copy it to an SD card which will go into the gps.

But here I am stuck.

Has anyone done this that could give me some pointers please?

Here is a link to the YT channel that explains it.

I followed this advice.

https://www.4x4community.co.za/forum/showthread.php/238631-OpenStreetMap-Topo-BaseCamp-Garmin-and-Android

Done it a few times with the newer version of the map each time.

I was happy with the result