Installation:

1: Install this mod:
https://www.gta5-mods.com/player/mai-shiranui-sp-insanogames-alex189

2: Extract the "lowr_diff_000_a_uni.dds" and "uppr_diff_000_a_uni.dds" files

3: Using OpenIV with Edit Mode enabled, add them to the "MaiSP.ytd" file