First, install Bakkesmod if you don’t have it yet.
Now the only thing you have to do is to install a Bakkesmod Plugin that will unlock the PRO Version of the map for you.
1st Method
Text Tutorial :
In Rocket League, press F2 to open the Bakkesmod Panel.
Navigate to Plugins, then open the Plugin Manager
Type “xxx” in the ID Case (top right) then hit the button <Install by ID>.
You are done, just launch the map and Play!
2nd Method
Text Tutorial:
Go on this page : https://bakkesplugins.com/plugins/view/13
Click on the “Install with Bakkesmod” button, then open the link with the plugininstaller.
A black window will open to tell you the installation status, when the black window tells you it’s finished, just launch the map and Play!
3rd Method (manual install)