I no longer have the game installed, so I'm not exactly sure what needs to be updated. one thing you could try is to rename LiliUnderwear.pak to LiliUnderwear_P.pak . I remember the game would update by adding _P files, and to mod those, the pak had to be named with the same _P at the end. So I am guessing maybe they updated that costume in someway in one of those _P files, so renaming it should work. If it doesn't, then I'm not sure what to do.