Need a little help with a cut

I am new to solid works and i need a little help. I am trying to cut a 45 degree angle into a rib that i created. I want it to cut away the rib but not intersect the other model objects. I guess my question is how do i do this using the sketch i created, or how should i have done this? I have attached the model, im sure this is a simple fix i have just came up short. Thanks so much for any help i can get. SolidworksParts And Features