This is the link to the andymark short C channel
http://www.3dcontentcentral.com/secu...d=171&id=13570
You can insert a cut feature to remove the material you dont want. Remember what side you are cutting because the holes are not symmetric on the front face.
You can also edit the first feature sketch, but the sketch is fixed - so delete the relations and then add dimensions.
Let me know if you need help. Marie