I received this from VF and it worked quite well. I used an old tee shirt and a sock on my iron.

"However there is a very good fix for the dents and they can be fixed almost to perfection! The way to do it is as follows.

Place a soft cotton cloth over the dented area and apply a hot iron gently right over the dent, giving it localized heat. Start with a low temperature and proceed to increase temperature slowly. At some point when enough heat is transferred into the dented foam, the foam will expand and push the dent out. Stop heating immediately when this happens and rub smooth with a soft cloth. Do not touch the hot iron directly to the red covering as it may melt or get deformed, this is why some tempering of the heat is required by placing a soft cotton cloth between the iron and the wing. Once the dents pop out, leave the wing in the hot sun for 3-4 hours, to help dry the glue which might still be damp inside the wing skin. These airplanes are being shipped immediately and often the aliphatic glue used to glue the wing skin to the foam core is not cured for some time. It does not affect the overall strength, but basically renders the skin soft and susceptible to local dents. Once all the moisture inside the wing is gone, it will be lighter and have a harder skin."