http://www1.agric.gov.ab.ca/$department/deptdocs.nsf/all/eng8090
If the fan is rotated by a hyd motor, then you need a supply of fluid through a motor valve.
It depend on what you have now. Can you describe your hyd system, such as, I only have a hyd pump and 3pt, or something similar.
If you do have remotes, you plug in the hyd hoses to the remotes and bungee the valve spool open for hyd fan operation.