Is there a way to keep all of the Half-Life content in Garry's Mod, but uninstall the games to free up disc space?

I looked at my Steam folder, and it’s over 98 gigabytes.
That is WAY too much for me. I’d like to uninstall Half-Life 2, Episode 1, Episode 2, and Lost Coast from my computer to free up some space, but I use the textures and foliage for maps and stuff in Garry’s Mod.
I don’t play the Half-Life series because I like to start a series from the beginning (and I don’t own Half-Life: Source).
I’d also like to do this with Counter Strike: Source and Team Fortress 2.

Is this a possibility, or am I just stuck with them on my computer so I can do things in GMod?

Also, sorry if this has been asked before – I tried to Google, but I couldn’t word it right to get an answer.

copy + paste the matherials, models, etc, into your garrysmod directory.

Tried the above and it crashed when I tried to open a Counter Strike map.
Any other ideas?

Maybe you could uninstall but keep the GCF’s? :tinfoil:

If keeping the GCF didn’t work, then turn your GCF into an addon. Here’s a good guide on how to do this:

wow, i never knew you could do that, this’ll be an interesting read!