I've done it several times and it's not hard to do. Here's all you ever wanted to know about it from the Windows 7 Help and Support:
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"<i>Redirect a folder to a new location


Redirect a folder to a new location</i><div><i> You can change the location
of the folders in your personal
folder (such as My Documents and My Pictures) by redirecting them. For
example, if you have a large number of files in your My Documents folder, you
might want to store the files on a different hard drive or on a network
to free up space on your primary hard drive.
When you redirect a folder to a new location, you change where the
folder, as well as the files in the folder, are stored. However, you'll still be
able to access the folder the same way you did before you redirected it.
Tip


Instead of redirecting a folder, you might want to consider
including a folder in one of your libraries. For example, if you have a large
number of pictures, you can store those pictures in a location other than your
primary hard drive, then include that location in your Pictures library. For
more information, see Include folders
in a library.

The Location tab in the Properties dialog of a
folder
To redirect a folder to a new location


Click the Start button ,
and then click your user name.

Right-click the folder that you want to redirect, and then click
Properties.

Click the Location tab, and then click Move.

Browse to the location where you want to redirect this folder. You
can select another location on this computer, another drive attached to this
computer, or another computer on the network. To find a network location, type
two backslashes (\\) into the address bar followed
by the name of the location where you want to redirect the folder (for example,
\\mylaptop), and then press Enter.

Click the folder where you want to store the files, click Select Folder, and then click OK.

In the dialog that appears, click Yes to
move all the files to the new location.
To restore a folder to its original location


Click the Start button ,
and then click your user name.

Right-click the folder that you previously redirected and want to
restore to its original location, and then click Properties.

Click the Location tab, click Restore Default, and then click OK.

Click Yes to recreate the original folder,
and then click Yes again to move all the files back to the
original folder.
Note


If you don't see the Location tab in a folder's Properties dialog,
then the folder can't be redirected. If you see the Location tab but can't edit
the folder path, then you don't have permission to redirect the folder. For more
information about permissions, see What are
permissions?"</i> </div>~~~~~~~~~~~
Good luck.