If this is for school, you should really figure that out yourself or with the help of classmates. If its for work, ask your co-workers what the preferred method is for your company. In reality, there are many ways to approach that part design.
My point being; what we tell you here may go against your companies guidelines. But if your curious about just the spiral, consider running a helix created in the GSD workbench. Use the helix as a guide for a rib.
As with any design, Company Standards/Guidelines tend to dictate the most favourable approach... Design Table? Modularity? Emulate process steps? Solid/Surface? Quick&Dirty/Stable?
