How do I cut out a diamond shape on a cylindrical part?

[caddgirl]

I drew a circle, cut it into 4 pieces and extruded 1/4 of it. Now I need to cut a diamond shape out of it following the arc? I can't wrap my head around this ... Please advise. I'm using Solidworks. Thanks

 

[bvanhiel]

Try the solidworks forum. When you do, post a picture, as I can think of several different ways to interpret what you are asking.

-b