I wrote an howto on the old forums unfortunately their closed now, but
this is what you should do to make them work:
download the .edj file, from terminal go to where the .edj file is located,
write edje_decc name_of_the_edj_file.edj a new folder with an .edc file in it would be created. open the .edc file with any text editor
change the line: name:"e/desktop/background";
to name:"desktop/background"; and save the changes.
then run build.sh from the same folder and a new and working .edj file will be created in the folder, copy it to the backgrounds folder (.e/e/backgrounds) or add it to backgrounds from the configuration panel, and you're done.
note: the backgrounds from get-e don't work right away on elive gem because it's using an older version of e17, backgrounds on later versions of elive would
probably work without changing nothing.