To enable RealVNC, you first need to install the VNC Server on the computer you want to control remotely. After installing the software, open the VNC Server application. You will need to either create a new RealVNC account or log in with an existing one. Once logged in, you can configure the settings, including access permissions and security options. Ensure that the VNC Server is running, and take note of the IP address or hostname of the machine for connecting later.