Things You'll Need
Instructions
Download a custom model or skin of the game's protagonist. Skins are typically available on a variety of file-hosting and fan sites dedicated to the game, such as GameBanana, MobDB and Planet Half-Life. (See Resources.) The downloaded file will more than likely be a compressed folder.
Extract the compressed files with the file-extraction program of your choice, such as WinZip, WinRAR or ExtractNow. To extract the files, right-click the file and click "Extract..." to bring up a standard Windows Explorer. Choose a folder to extract the folders and files into.
Copy the uncompressed files and folder into the game's "Models" folder. This folder is located wherever you specified the game to be installed during the installation process. By default, the path is located in the "Steam" folder, and the "Models" folder is located in the "Gearbox" folder. When you paste them into the folder, the files will need to overwrite a variety of files and previous skins. Click "Yes to All" to approve these changes. The customized character will be loaded the next time you start the game.