To install a new Role for a server run the "Add Roles" action that is available at the root of the "Roles" node in Server Manager. This will launch the Add Roles Wizard. Click Next to the main welcome screen, which shows the roles that can be installed. Note that Roles already installed are shown as grey ticks (you cannot uninstall a role via the Add Roles wizard nor can you change role services for an installed Role.) After you select the Roles, the navigation area of the dialog box will change to show modified stages that reflect selecting role services for the role selected. When You install the DHCP role, you can configure basic scope options within the Add Server Role wizard.
To modify the Role Services for a specific role, select the Role within Server Manager and run the "Add Role Services" wizard. To add features, run the Add Features action that is available via the Features node of Server Manager (there are no services within a Feature) and no configurations are performed via the Add Features wizard.