Instructions
Visit The GTA Place's "Downloads" page (see Resources).
Click on the link at the top of the page which corresponds to your GTA game. For example, if you want to download vehicles for GTA IV, click on the first link listed. The options are GTA IV, GTA San Andreas, GTA Vice City, GTA3, GTA Chinatown Wars, GTA Vice City Stories, GTA Liberty City Stories, and GTA multi-player (in that order).
Click on the vehicle you wish to download on this next page. Choose a category from boats, bikes, helicopters and cars/vehicles, and then click on the type of vehicle you want to download. There are many choices for a lot of the games, including Yamaha bikes, Porsche cars and S.W.A.T. police vans.
Click on the blue "Download" button under the file information halfway down the page. Click "OK" with the dialog box pops up to download the file. WinZip or WinRAR will open automatically.
Highlight all of the items in WinZip or WinRAR and click on "Extract" at the top, or right-click and choose "Extract." Click on the top location on the left-hand panel, "Desktop." Click on "UnZip."
Replacing the Mod on PC
Click on the Image Tool 2 link in the Resources section.
Click on the blue "Download" button on the right-hand side of the page (near the middle) to download Image Tool 2. This is a tool needed to get the mod to function properly in your GTA game.
Click "OK" to save the file on your computer and double-click on the file name once it is saved. WinZip or WinRAR will open.
Right-click on IMGtool.exe and click on "Extract." Click on "Desktop" on the left-hand panel and then click on "UnZip" at the bottom. Open that file from your desktop ("IMGtool.exe"). Insert your game disk into the CD-ROM drive.
Click on "File" from the toolbar on the top of the Image Tool program and click on "Open." Click on "Computer" on the left-hand side and open the drive where your game is located (usually E:). Locate the original vehicle file you want to replace within your game drive. Click on "Commands" on the toolbar at the top and on the first option, "Add." Add the file you extracted in Step 4, and now your game will have replaced the original game vehicle with the new vehicle you downloaded.