Jiffy Reefing is a very easy project if you have the gromets all ready on the Main. In the picture below I show the rigging of a Jiffy Reefing System. The Main and Boom are transparent so you can follow the flow of the Reefing Line.
1. Length of 1/4" line.
2. 3 screw down eye straps.
3. 2 bullseye fairleads
4. 1 small Lance Cleat
First you'll want to mount two of the eye straps on opposite sides of the boom a little aft of the grommet closest to the leech of the Main. By mounting these aft of the grommet the line will pull aft on the Main in the Reefed position acting as an outhaul.
Next place an eye strap on the boom just below the forward Reefing Grommet.
Next mark a position on the Mast at about the same height as the eye strap you installed in the last step.
You will need to mound a turning block near the base of the Mast to direct the line to the port and aft.
Next mount a bullseye on the cabin top to direct the line aft to the Lance Cleat.
Finally mount the small Lance Cleat on the cabin just before it drops off to the cockpit.
Thread the line as shown.
You have to drop the halyard the amount that your Main Reefs to before you can Reef the Main.