Things You'll Need
Instructions
Getting the Tools Ready
Download and extract the FFXI Dat Copier to your hard drive (see Resources).
Double-click on "FFXI Dat Copier.exe" to start the program.
Select the folder for your FFXI installation (usually "C:\Program Files\PlayOnline\SquareEnix\FINAL FANTASY XI"), folder for your downloaded Dats and a folder for backups.
Find Dats online (see Resources) and place them in the folder you made for your downloaded Dats.
Using and Changing the Dats
Click the Race option at the bottom of the program window and select your character's race.
Click the box next the "Input" field and select the Dat you wish to use.
Click the "Type" option to select what you're replacing such as a weapon or a helmet.
Select what you wish to replace under the "Output" menu. These steps are telling the program that you wish to replace one of the original Dat files with one of your own choosing.
Click "Copy Files" to perform the Dat replacement. You will now see your Dat files when you play the game.