Open the auction then click over the options. When you get there you should be able to "revise". Sometimes it is too late in the auction to change. I am not sure when their cutoff is, but if you can't go under shipping and correct it to "free" then just Make a 'note" it will post under the auction info. And if that doesn't work, just put a general message on there, like under this message, explaining that shipping is in fact free. It won't help to change the search criteria doing it that way, but anyone that opens the auction will see it. As a last resort you could delete and re-list the auction together, however its not recommended towards the end. But most people will understand! You would have a lot more bids if it was listed as free so I would understand! Good luck!