Wear latex gloves for several hours until your hands perspire thoroughly. Then take off gloves and wash with soap and warm water. I have personal expirence with this technique and it really works..... It is so adhered, you will pull off layers of skin if you chisel off foam. good luck
You need to determine first if the foam insulation is harmful to your lungs. Secondly,you may be able to buy a removal product for the insulation. If not, tou might have to chisel it out one piece at a time.