Regarding tutorial no I don't have video tutorial, it's quiet easy anyway. Install it like you install any mod. Either rename it to C1 and overwrite your original C1 (Take backup copy first) or copy it as it is and then use costume unlocker to use it in game. Make sure you correctly modify costume unlocker first to work with DLC chars.
It works both ways either rename the files and overwrite on C1 (Take backup first) or use with unlocker but at the moment we don't have a proper unlocker to work with all chars (including DLC) so you have to modify unlocker to work with them here is the guide.