Lego Star Wars MCTP Version 1.4 (old) file

If your game is in Program Files, which is likely, it will have to be moved or reinstalled in another location.
If you have the game through Steam, you will make a new Steam library folder in Steam's Download settings, then go to LSW's properties and click "Move Install Folder" in the Local Files tab.
With the game moved out of Program Files, I believe Texmod will work.
I realize this is not very convenient.

Extract Texmod.exe and Lego Star Wars.tpf to a convenient location. Run Texmod (be sure Steam is running if you own Lego Star Wars through Steam). In Package Mode, select LEGOStarWarsSaga.exe as the target application. Select Lego Star Wars.tpf in the "Select Packages" box. Click "Run" at the bottom of the window to launch the game. You will have to launch the game through Texmod every time you wish to use this pack. If it works, the splash screen should show Disney and Lucasfilm logos in place of the Lucasarts logo.

If you've done everything correctly and it still doesn't work, I've been told it's possible to make it work with OpenTexmod. I have not personally tried this.