This is a method to install the mod in SF X TEKKEN, SSF4AE & USF4 without messing with the original files, so there is no need to backup them. (discovered by ~robhal (https://www.deviantart.com/robhal)).
Street Fighter x Tekken
1. Create folder "chara" inside this folder "...\Street Fighter X Tekken\patch\CMN\battle\".
2. Create folder for respective character, eg: ASK, KEN, LIL, RYU, etc...
3. And finally just extract or copy the mod into above folder.
4. Run the game to see the result.
Super Street Fighter 4 Arcade Edition
1. Create folder "battle\chara" inside this folder "...\Super Street Fighter IV\patch\".
2. Create folder for respective character, eg: CDY,