If this is your very first time using the Live Push feature, then you will need to set up the connection to the website and get the connection approved by a Website Admin.  This can be done by going to File >Settings then clicking on the "Site Access" tab.  From here you need to copy your websites URL into the Site Address field and then click "Request Access".

Next, you will need to get approval through the website by an Admin.  Users can be approved for live push access under Additional Modules > PIM Live Push in the site Admin panel. Simply click the "Accept".

In the image above, we have an item without a Web Description.  To see what the item would look like with a Web Description, we first need to add one to it.  To do this, see our Viewing and Editing Items in the PIM article.

Once you have the item(s) selected and the change has been applied, right click on the item(s) and select "Live Push" from the menu.  When Live Push starts, a Live Push Progress bar will appear. 

On your first attempt to Live Push during the current session, you will be prompted to login.  These are the same credentials used to log into the website, NOT your PIM credentials. 

Select whether you want to re-upload associated images and documents with the Live Push.  If you say "No", only the item data will pushed to the website, and not associated images and documents.

Once Live Push has finished, refresh the page to see the changes you made.