Copy tarball to boot under Gnome
Steps
Screenshots are from GNOME but most GUI desktops are similar.
Select install tarball wherever you have it downloads (often in your
Downloads
directory), right-click and select ‘Extract To…’Select the boot partition of the SD card as extraction destination
The result will be a directory containing the boot files on the boot partition; we actually want the files in the top-level (root) of the boot partition.
Therefore, select all files in the directory that was created (e.g. in the file manager, browse into the directory and press [Ctrl-A]).
Remove the now extraneous extraction directory (which should be empty).