(INSTALLING)

Open:OpenIV (If You Don't Have It. Here You Go)( http://openiv.com/ ) 
Enable Edit Mode 
Go To: C:\Program Files (x86)\Steam\steamapps\common\Grand Theft Auto V\x64v.rpf\models\cdimages\streamedpeds_players.rpf\player_one
Then Place " uppr_diff_004_a_uni.ytd " There
And You Are Done