Wedding dress alterations-possible?

Unfortunately, that dress ruffle is cut on the diagonal (called "bias") Idid alterations on almost the exact same gown - we pulled out 2 layers of the "under tulle" so the dress wasn't as puffed out. This made all the outer layers lay flatter and smoother.

What you are wanting is a whole different skirt. It would probably be best to get a different dress. Otherwise, you would need to take the skirt off and replace it with the look you want.