1.Open OpenIV
2.Turn on Edit Mode
3.Navigate to - Grand Theft Auto 5/mods/update/x64/dlcpacks/mpbiker/dlc/x64/models/cdimages/
mpbiker_male.rpf/mp_m_freemode_01_mp_m_bikerdlc_01 -
4.Drag and drop the ( ydd + ytd ) files into the directory.
5.Close OpenIV and play.
6.enjoy!