In order to install .OIV
You'll need to have OpenIV openiv.com installed

If you've done that
open up openiv with the game Grand Theft Auto 5
then drag and drop .oiv file into the window of OpenIV
it'll start the installer



With uninstaller
after uninstalled you must remove line <Item>dlcpacks:/bahama/</Item>
from mods/update/update.rpf/common/data/dlclist.xml manually 