Tapering complex geometry with flex

Hi all,

I'm not intimately familiar enough with the flex tool to determine whether or not I can do something with the flex command, but here is what I am trying to do.  Let's say I have the following shape.  I would like to taper shape either symmetrically or asymmetrically.

I am not creating this shape, but am just using it as an example as the geometry I have has a lot of surface features on it.  With that said, I don't have the luxury of starting from scratch and need to deform the existing geometry.

Thanks.

SolidworksParts And Features