Import it into wings and make a series (not just one) of edge slide morphs of varying degrees, ranges and strength. Apply the lot and fiddle with mixtures and bake the results that work for what you are looking for. If you mess with scaling on the boobs quite a bit it's useful to have more than one version of an adjustment morph dial available to make finer adjustments when the limits of the initial dials usefulness reaches it's apex for a particular scale. This probably doesn't seem to make sense but it's just a practice I've adapted from my personal experiences with this. Sculpting tools are limited for such things, you want to slide loops if possible.