Then turn the candle upside down and place it into a cup or bowl that will securely hold it upright. Think of it now as a candle mold.
You will need to seal the bottom of the candle though. I do this by pouring a teaspoon or so of melted wax into the bottom. This will seal the hole that the wick goes through.
Attach a wick bar or other support to the top and you're ready to pour the inside.