Rhino 5 and Grasshopper Installation

Hello, Ive been using Grasshopper w Rhino 4.0 for years.  I was usinig Grasshopper 0.9.0056 and ran into some problems baking things.  They just wont bake.

Anyway I just downloaded Grasshopper 0.9.0062 and cant not figure out how to install it?

The file that download is a .RHI file and if I double click it it launches Rhino 4.  Not sure and read I may have to do this manually.  When I go to plugins and install the file type is not recognized? Any suggestions?

Thank you,

Jim G.