First of all you need to download the software from Microsoft. In the Microsoft Download Centre these are called "Remote Server Administration Tools for Windows 7" a direct link to the download page is given below;
If you scroll down to the "Files in This Download" section of the page you'll see two files. Depending on whether or not you're running 32-bit or 64-bit Windows 7 you need to pick the correct file. If you're unsure of which version you're running then go to the start button, right-click "Computer" and then select "Properties". You'll see something like this;
|System Information (64-bit/32-bit)|
If you're running 32-bit then you need to download the file which starts "x86..." (currently this is "x86fre_GRMRSAT_MSU.msu" but it might change). For 64-bit users you need to download the file which begins "amd64..." (currently this is "amd64fre_GRMRSATX_MSU.msu") - this is true even if you're running a non-AMD 64-bit processor. The reason for this I'll leave Microsoft to explain ...
Once you've got the file install it (it's a standard KB update file).
After it's been successfully installed go to the Start Menu > Control Panel and select "Programs";
|"Turn Windows Features on or off" under "Programs and Features"|
|"Windows Features" dialog|
In order to make finding these under the Start Menu a little easier right-click the Start Button and select "Properties";
|Taskbar and Start Menu Properties|
|Customize Start Menu|
|Active Directory Start Menu Items|