#1. You will need to download a small program called "IMGTool". This allows access to the "gta3.img" which stores the .DFF's - .DFF is the file which stores models, TXD's - TXD's contain the textures assigned to models, and COL's - COL's are the Collision files which make everything solid. You can download IMGTool Here!
#2. Using WinZip (Limited trial) or 7zip (Free), extract "imgtool20.zip" to the desktop.
#3. Open the GTA:SA folder. If you used the default installation options, it will be in the C:/Program Files/RockStar Games/Grand Theft Auto San Andreas. Open the Models folder, and locate the file named "GTA3.IMG". Right click the file and choose "properties", which is at the bottom of the menu.
#4. A dialog box will apear. It will look like this (If it doesn't, retrace your steps and try again):
#5. You will see that I have outlined the "Read Only" checkbox. We need to uncheck it, as read only stops the files from being editable. Click inside the box, and it should look like this:
Click the outlined Apply box. The files are now open to edit.
#6. Now you need to open the "IMGTool.exe" file we downloaded earlier. The folder will be named "imgtool20". Run the EXE, and you will get a window that looks like this:
#7. Now we are going to decide what modification we want to install. I will be adding and replacing a default car for this tutorial.
#8. In IMGTool, navigate to File > Open (Or CTRL+L). Navigate to C:/Program Files/RockStar Games/Grand Theft Auto San Andreas/Models/gta3.img. Choose the file and click open.
#9. Do not worry if IMGTool momentarily freezes, the gta3.img is almost 1GB in size. Once opened, you will see alot of files, it will look like this:
Go back to the GTA SA folder. Create a new folder called BACKUP:
#10. In IMGTool, search for the file names of the mod you are installing. For me, it will be "Admiral.dff" and "Admiral.txd". Right click the file, and choose "Extract". Select the BACKUP folder we made earlier; this will help if the mod malfunctions and crashes the game. Do the same process for each file.
#11. Proceed to delete the old files from the IMG:
#12. Now we can add the new files. Press CTRL+A to open the "Add" dialog box. Navigate to the modification folder and choose the new file(s).
#13. For some reason, editing the IMG in SA only allows you to add ONE file at a time, whereas with Vice City you can add two or more files. Select the first file, and click "Open". The first file should be added. Do the same for the second. Remember you can only add ONE file at a time, many times have I tried to add two and thought it worked. It's a small thing to overpass.
#14. Go to Commands > Rebuild Archive. This will refresh the IMG file and make sure the new files fit in.
This may take a few minutes. Once done, close IMGtool.
#15. Now test GTA:SA; If the mod works, congratulations! - If not, retrace your steps and try again. It may take a few tries.
Tutorial written and produced by .ash. Do not repost without permission.