Check out my Tutorial on how to make your own clothes :)
https://www.youtube.com/watch?v=M1zlmMWO76o

Installation:

1. Open OpenIV
2. Go to GTA V/x64v.rpf/models/cdimages/streamedpeds_players.rpf/player_one

Replace this file:
uppr_diff_004_m_uni.ytd

With the one i made :) (make sure you're in edit mode)