Under Content and Files> Custom URLs.  From the Custom URLs main page, click the

1. "Add New Custom URL" button to configure a new URL redirect
2. Edit an existing redirect

1. The Requested URL would be the old URL, or the URL that is requested by the visitor.
2. The Redirected URL is the actual page where the visitor will end up.
3. Move Permanently will add the additional code necessary to inform the search engines that the old page no longer exists.

You have the ability to upload multiple custom URLs as a spreadsheet.  You can see an example spreadsheet below.

As you can see, you only need three headings, and they correspond to the fields on the edit/add url page:

1. RequestedUrl - This is the url you want to be redirected from

2. RedirectToUrl - This is the url you want the prior to redirect to

3. MovePermanently - Entering TRUE/1 here will check the "Move Permanently" box, FALSE/0 will leave it unchecked.