gj fam

With great difficulty. I had to delete or compress a few to make them all fit.
It's a bit of a waste, since they are poor quality, and don't appear until after addons have mounted, unlike if you put them in a folder under \garrysmod\addons\<addon name>\gamemodes\sandbox\backgrounds.

I have no intention of ever updating this addon, and I've fallen out of the habit of playing Gmod for a while.

How did you manage to get all of these backgrounds into one addon?

Nice meme