How to modify IIS role services in Windows Server 2012?

Go to Server Manager, or type "servermanager" at a command prompt. The GUI Server Manager will pop up.

Click the Manage dropdown up in the top right. Choose "Add Roles and Features."

Click next, next, select the right server, click next.

Now you should be on the Server Roles selection. Expand IIS (which will be greyed out since you have already installed it.) But the features or role services or whatever you want to call them, such as WebDAV Publishing for example, will not be greyed out because you haven't installed it yet. So click it.

Hit next, next, Install. Add and remove role services at will.

Please find the Screenshot: