Opening and Extracting the .big Files

So you want to open the .big files do you? Well only proceed with doing so if you either know what you are doing, or are willing to reinstall the game if you screw up. 

Step 1:
You need to download the following utility:
FinalBig 

Step 2:
Unzip the FinalBig zip 

Step 3:
Open the FinalBIG.exe program from the unzipped folder 

Step 4:
Go File Open. Select the .big file you wish to open. 

You've now opened your .big file. Continue on if you wish to know how to extract. 

Step 5:
Go Edit, Extract All. 

Step 6:
Select a folder you wish the files to go into and hit OK. 

The files are now extracted and ready for you to modify.