-Start OpenIV
-Make sure you have a modified gameconfig.xml that could handle add-on vehicles with no problem, if you have a modified gameconfig installed, skip this step
-Put the "prisontransport" folder on update/x64/dlcpacks/
-Click Edit Mode, then go to update.rpf/common/data and find dlclist.xml
-Extract and edit the dlclist.xml
-Copy this line:
		<Item>dlcpacks:/prisontransport/</Item>
-Save it and drag and drop the dlclist.xml to update.rpf/common/data/
-Extract the vehicles.meta from update.rpf/common/data/levels/gta5/
-Open "Update.rpf Vehicles.meta" and follow the instruction inside the "meta" text file
-Drag the vehicles.meta back to update.rpf/common/data/levels/gta5/
-After following the whole step, start the game and enjoy

OPTIONAL
If you want to make the vehicles to spawn at some places, place "prisongen" to dlcpacks and do the same step above.
