Step 1: Navigate to Steam Community :: Steam Workshop and find a source engine game that's heavily modded, such as Garry's Mod
Step 2: Look for the model itself, start by opening the model category here:
Step 3: Now download crowbar, you can download it on github via GitHub - ZeqMacaw/Crowbar: Crowbar - GoldSource and Source Engine Modding Tool, this tool is a source engine modding tool that will allow us to extract the contents from the steam workshop.
Save it somewhere then run it and you'll see this screen.
Step 4:
Let's make a folder in our Documents called Models or something, then open the second tab in crowbar.
Here you can see I've pasted the steam website link for the model into the "Item ID or Link" box, then set it to output in the model folder I made.
Click download when you're ready.
Step 5: When it's complete like the image shows, click "Use in Unpack" in the bottom right corner.
This will open this screen, click the green refresh icon if there are no folders and it'll reload the asset, click unpack when your screen is looking similar.
Step 6: Now if we navigate to the folder we extracted it to, you'll see a bunch of files in there, we're only interested in "models" Go in there and search for the "mdl" extension files that we have generated, keep that in mind, for reference, mine is doge_player.mdl
Step 7: Next, open the decompile tab and import your model you had just created, we'll also set the output folder to be a sub-directory to keep it simple, then click decompile when we're ready!
Step 8: Next, download blender from blender.org - Home of the Blender project - Free and Open 3D Creation Software and install it.
Step 9: Navigate to this page and download Blender Source Tools, follow the instructions provided on the site Blender Source Tools
Step 10: Next, we're going to import the .smd file we generated from the .mdl file in step 7, this should be where the .mdl file was but inside a sub-folder.
Step 11: Now we have our model we stole from the workshop! Decimate it to reduce the poly-count or whatever, then export it to .obj to import into metaseq.