You'll need these programs and your image editor of choice.
L4D2 authoring tools can be found by searching it in your steam library.

First open GCFScape, go to your L4D2 game directory (for me it'll be "D:\SteamLibrary\steamapps\common\Left 4 Dead 2\left4dead2") and drag the file "pak01_dir.vpk" into GCFScape.


In GCFScape, go open materials, then press Ctrl + F and search for the thing you wanna mod, if it doesn't show up, im sorry i cannot help you, you'll have to search for it manually :(
For this guide, i will mod the M16. If you used the little window to find your texture, right click on the result and click "go to directory".

Once you found the files, extract the files onto your desktop (you can do this by dragging them) and create your mod folder like this

Now open any of the vtf files you extracted in your image editor of choice and start drawing!




Once you're done export it as a TGA file.

Now open VTFEdit IMPORT your TGA file, click "save as" go to your mod folder and replace the current VTF file with the new one.

Go to your mod folder, create a text file called "addoninfo" and copy & paste this into it:
"AddonInfo"
{
addonSteamAppID 550
addontitle "mod name goes here!"
addonversion 1
addonauthor "your name goes here!!"
addonDescription "something idk"
}
it should look like this.

now put your Mod folder in the addons folder for convenience sake, open your bin folder aswell, drag your mod folder into "vpk.exe" and it should create a vpk file.
after that, move the folder version of your mod somewhere else and launch the game to see if it works!

(its beautiful...)

Uploading is pretty easy, open the L4D2 authoring tools, click workshop manager, click the plus sign and fill out the requirements.

ok thanks for reading now give me steam awards please :3