I realize this is an old post, but I came to it seeking the same answer, and was unable to find anything else out via searching. In order to access the Excel Connector in Excel 2013, install everything as normal (Download the Force.com ToolKit and install, download the proper version of the excel connector, and install via the add-ons within Excel). After this, go to the downloaded excel connector file and open it directly. This will prompt the Macro Security check that does not get prompted during the standard installation process with 2013 (but does with 2010 and 2007). Once security is authorized, close the program, and re-open Excel as normal. The connector will now be available in the Add-Ons tab just as previous versions of Excel.