after intalling the wrong role in Windows Server 2012, I got the idea to blog how to remove the role.
1. First open the Server Manager.
2. Klick on “Manage” and than on “Remove Roles and Features”.
3. The wizzard starts.
4. Now you have to select the server were you want to remove a role.
5. Select the role you want to remove.
6. If you want to remove a feature, you can select it in this menu.
7. Now you get a small of all actions that will be performed. Klick “Remove” to start the actions.