Super easy! Plastic cup wrapped in Cocoa Krispies drizzle chocolate to create lava. Add hot water to the cup and dry ice chunks. If I were to make another I would use a cup with a handle and place a piece of cardboard between the cake and volcano so it can easily be removed to empty the contents of the cup frequently ( we showed it off all day) Also warm water first then little chunks of dry ice. It will melt and fuse together making it difficult for it to do its job otherwise.