How to set .net 4.0 or 4.5 on Server 2008 R2

I haven't done this since 2004, and everything is different. I'm going to the Server Manager on 2008 R2 and looking at the features selected, and I see .NET Framework 3.5.1. And can remove it, but when I click on Add Features, .NET Framework 4.0 is not there to select. I can go to C:\Windows\Microsoft.NET\Framework and see a v4.9.30319 there.

How do I get it to where I can select the 4.0 version? How can I get 4.5 on the server?

Thank you,