How do I draw this?

Hi all,

I have been given an IGES file with the geometry shown below.

I need to make some modifications to it, but as the IGES imports as a solid, it is not as easy as I would like.

I have tried to use FeatureWorks to recognise the features, but it picked up fillets only.

I would like to model the geometry from scratch, so I have control over it, but I don't know how to create the cuts around the body of the part.

I would be gratefull for any advice you can give me.

Thanks in advance.

SolidworksParts And Features