So ! , lets get started!
1)first we need to download a program called: Notepad++
Link: Click here
(lets download npp.5.1.2.Installer.exe)
now we'll install the program ( you have to do it alone since its too simple to be included in this tut )
2)now we need to find a file called pak01_dir.vpk which is located in: Steam/SteamApps/common/left4dead/lef4dead/
now we have to Open pak01_dir.vpk with notepad++ and now we need so search for lines which we need to change (for eg i'll use my pc screen skin : Click Here )
so now we need to use Ctrl + F combination which stands for Search and we paste desired line , in this case:
$baseTexture "models\props_interiors/screen"
and we're changing the file path to $baseTexture "models\props_interiors/screen2" to make game search for content in its folders (warning , you need to check skin filenames , cause every skinner can name their files differently so not always you'll have to just add 2 at the end , sometimes you'll have to change entire filename!)
3)after the work's done we use CTRL + S combination which stands for save (warning before saving , starting to edit close EVERY other files opened in Notepad++ , i was experiencing troubles ingame when i saved pak01dir with several other files opened with it!)
4)paste skin files into specified folders and start the game ENJOY!
P.S:i'll add some helping screenies later and some HTML coding