Ok. What you need is:
1. Hex editor (I prefer HxD)
2. Monsters, Inc. (Obviously)
3. UltraISO (or a program that can reimport and rebuild ISO files)
4. Text editor such as Notepad++
Step 1. Open the ISO and navigate to the "levels" folder.
Step 2: Open up the "scareflr" folder (for the sake of this tutorial)
Step 3. Extract the "scareflr.LV2' and "scarelfr.WAD" file to your desktop (or any place where you can remember where you put it)
Step 4: Open the .LV2 file with Notepad++ and type in the search field "sully"
Step 5: Replace the resource name with "randall". This replaces the model and textures, but not the animations.
Step 6: Save the .LV2 file
Step 7: Open up the .WAD file in HxD (or whichever hex editor it is you want) and search for "sul_run".
Step 8: Replace "sul_run" with "ran_run" and then search for "ran_run" and replace that with "sul_run".
Step 9: Save the .WAD, and replace the existing .WAD and .LV2 files with the modified versions you just did, and save the ISO.
Step 10: Play the game, and if you did it right, Sully should now be Randall, and should use Randall's running animation!
Here is a list of all of the animations used by the game:https://www.dropbox.com/s/jburho1dys9ec ... S.rtf?dl=1
And, keep in mind, make sure that if the animation name is longer than the other, make sure the name's offset ends with 0.