Final Fantasy X change models

[Contessa]

hello everyone
for my first time of playing final fantasy x , i loved the game also i finished it wihtout cheats so from my habits when i finish some game i play it again
but with cheats,mods...
that what i do with our game final fantasy x , but the problem is when i saw many youtube videos about you can change some party member model to someone else like enemies models..etc i liked this but when i search for how to making this i didnt find anything so can someone help me or tell me how to do it please and thanks.

example video :
https://www.youtube.com/watch?v=XFG42stjkts

[Frozen_Raven]

As is written on the video itself with a tool called FFXED, I have used it myself but it is extremely buggy so I don't recommend to use it as the game will crash often.