Setup
No account, no configuration, nothing to uninstall first. Works alongside the official client inside the Jagex Launcher.
Take the Windows .exe, or the universal .jar if you are on macOS or Linux. Both are small (around 12 MB).
Open the file you downloaded and follow the prompts. Nothing else to configure. It installs cleanly.
Quit it completely (check the system tray), then open it again. RuneLitePlus appears as a client you can pick.
Open the Jagex Launcher, select RuneLitePlus from the client list, and log in as usual. Plugins are installed from the Plugin Hub tab inside the client.
If RuneLitePlus does not appear after restarting the launcher, fully quit the launcher (including any tray icon) and try once more.
Windows 10 or later, macOS 10.14+, or any modern Linux distribution. Java is bundled with the Windows installer; the .jar version requires a recent Java runtime.