You have to learn Grasshopper. Grasshopper is free Rhino plugin.
old, basic Grasshopper tutorial: Grasshopper Getting Started by David Rutten - 01 - Interface Basics on Vimeo
old Grasshopper documentation: Grasshopper Primer - Mandatory Grasshoper reader, made by professor - StudeerSnel
latest Grasshopper tutorials: Latest Grasshopper tutorials