Run Rhino function Exturde Surface in
25.1 According to prompt selec contour in the screen.
25.2 Option BothSide=NO , it changes viewport to Front viewport and pulls surface toward Z- axis.

Move mouse to Rhino function Hide objects and hold down left mouse button for several seconds to pop up , run to show selected object(see figure).

Move mouse to Rhino function Retangular Plane in and hold down left mouse button for several seconds to pop up , run to create planar surface through objects at designated location.
27.1 According to prompt, it selects the heel in the screen(see figure).

27.2 According to prompt, it use two point to defines cutting plane, start point is near to the lowest point in the head of the sole and press Shift key to create horizontal line toward to the end of the sole(see figure).

Change to Perspective viewport, run Rhino function Trim to trim surface.

In the Perspective viewport, press Enter key or right mouse button to repeat the pervious function Trim.

Select objects , and run Rhino function Group to create a single unit.

Move mouse to Rhino function Select All and hold down Left mouse button for several seconds to pop up , runto select all curves and press Del key to delete.

Select sole in the screen and run Rhino function Object Properties , the setting shows as following dialog box, on the right side picture is setting result.

Run ImagineElf3D menu > Display > Panel > All to shows the all of panels.