Installing Openplanet is straight forward. First, download the latest version and run the installer.
During the setup, you will be asked to locate your install path for Trackmania. Make sure you enter the exact directory where
Trackmania.exe resides. (If you're installing the Maniaplanet version of Openplanet, you're looking for
ManiaPlanet.exe, and for the Turbo version it's
Careful if you've installed Trackmania through Epic Games, as it may have installed the game twice!
Openplanet needs to be installed in the same directory as the game you're actually running. You can double-check where the used Trackmania instance is located: Once Trackmania is started, open the task manager, right-click
Trackmania.exe and select to open its file location.
Once installed, simply start Trackmania like normal, and you should see "Press F3 for Openplanet menu" in the top-left corner. If the overlay doesn't work, check out the troubleshooting guide.