Sort of discussed indirectly a day or two ago in this thread.
Basically, either:
download a whole country from garmin.openstreetmap.nl's GUI if your device will support a file that size, as there'll be a direct download. Or you might be lucky if someone's already had a file prepared for a region of a country.
or install Garmin's BaseCamp application, and then download the BaseCamp compatible OSM map (see https://www.lfgss.com/comments/13550165/ for UK). BaseCamp will allow you to cut the map down and export it to your device.
Sort of discussed indirectly a day or two ago in this thread.
Basically, either:
download a whole country from garmin.openstreetmap.nl's GUI if your device will support a file that size, as there'll be a direct download. Or you might be lucky if someone's already had a file prepared for a region of a country.
or install Garmin's BaseCamp application, and then download the BaseCamp compatible OSM map (see https://www.lfgss.com/comments/13550165/ for UK). BaseCamp will allow you to cut the map down and export it to your device.