Delete contours to create spaces

[spacewarp]

I'm trying to create a letter O with a diagonal line through it.  In the attachment, I would like the diagonal bar to merely "cut" the ring.  How do I either split the contour into pieces so that I can delete them individually, or else have the rectangle match the inner circle color-wise, so that it is entirely white?  The "Reverse" function only makes it an "inverse" color, instead of "white/clear".

Attachments:

[Allan Murray]

If you reverse the direction of the diagonal line only (right click on a point and select reverse) I think you will get the result you desire.

This is not a complete solution though, because there should not be overlapping contours. With the full version you can use remove overlap on the contour menu to fix this. There is no easy way to merge the contours using Type light.