Changing silkscreen symbol from solid fill to unfilled

I'm using OrCAD PCB Designer Professional 16.5 in Windows 7. I'd really like to know how to change a silkscreened circle from solid fill to unfilled. In other words, just have a hollow circle where I can specify the line width.

Here's the information from Show Element:

LISTING: 1 element(s)

             < SHAPE >

       class         PACKAGE GEOMETRY        subclass      SILKSCREEN_TOP

  Shape is solid filled   Area:   0.0491  (sq in)

Exterior boundary:   arc seg:xy (795.00 1785.00) xy (795.00 1785.00) width (0.00)     center-xy:  (670.00 1785.00) radius (125.00)   CW