This map requires Menyoo PC. You have to have the latest patch of GTA V and the latest Scripthook V.
Once you’ve installed Menyoo you’ll have a “Menyoostuff” folder in your game directory.
Go to that, then drop the xml file(s) in your Spooner folder.
Go to Object Spooner > Manage Saved Files and select GTAMaps-megaRamp-25 from the list. Then select Load Placements.