If you have a Windows Server that has RRAS installed and you need to use your server for some other purpose, then before you remove the RRAS role from the server you should do the following:
1. Open the RRAS console and select your RRAS server
2. Right-click on your RRAS server and select Disable Routing and Remote Access
3. Wait for the RRAS service to stop.
4. Remove the RRAS role using Server Manager.
If you do this, the RRAS configuration info on your server will be deleted and the RRAS role will be removed, allowing you to install other roles as needed in order to repurpose your server.
But what if you don't disable RRAS before removing the role? Well, the role will be removed but the RRAS configuration info such as interfaces, ports, etc. will still be present. While this may not interfere with any new roles you might install on the server, it could cause problems for you later if you decide to re-install the RRAS role on your server since any previous RRAS configuration info could conflict with your new RRAS configuration.