You can't. The auction is over and the reserve was not met. You will need to relist the item. You can always touch base with the last bidder and maybe work with them on a BIN listing using their high bid as the BIN price.
As a side note there is also no way for you to recover the FVF's you were charged because you used a reserve setting and the auction did not meet that reserve and the item did not sell. If you are going to use the auction format best to simply start your price off at what you would have used for the reserve setting and avoid using the reserve .
