[Setting nozzle size in Cura 15.06]

I recently updated to Cura 15.06 on my Mac and at first impression, it is a lot more sluggish compared to the earlier.

I am a current user of the 3DSolex's The Olsson Block which allows for interchangeable nozzles.

I can't seem to find the nozzle setting under the latest Cura. How do I change nozzle size? I wish to change from 0.4mm to 0.8mm.

Thanks.

David