How do I import models from the Garry's Mod workshop into Blender?

Say I want to import the models from this mod into Blender so I can mess around with them.
How do I do that? In what folder is the mod located in and how do I extract the models? Do I need a program or an add-on/script for Blender in order to do that?

Addons are located in your garrysmod/garrysmod/addons folder. They are compressed into a .gma file, you use gmad.exe to decompress them, you’ll find the decompressed folder at the location where the .gma was.

You then need to use CrowbarTool (Google it) to convert the .mdl file into a blender-recognizable file. I recommend you look up the source blender tools plugin.

[editline]25th September 2017[/editline]

gmad.exe is located in your garrysmod/bin folder

I’ve successfully decompressed the files, but I’m having trouble with the Crowbar Tool - for some reason I can’t run it, and the source plugin for Blender only works with .smd files, not .mdl

Try this: https://developer.valvesoftware.com/wiki/Blender_Source_Tools