simple to do
Just run a line from near the end of the boom, up thru the leech cringle, back down and thru a cheek block below the cringle. Continue runing the line forward towards the goose neck fitting. Place another cheek block there at the end of the boom. Run the line up thru the luff cringle and back down to the base of the mast. Put a block there and another block on the cabin roof to turn the line back towards the cockpit. At the edge of the roof, put a clutch or cam cleat with a fairlead.When you want to reef the main, turn up into the wind, take up the topping lift or clip onto the pigtail. Ease the main halyard to a premarked spot. Pull in the reefing line until the mainsail's reefing cringles are down to the boom, and lock it in. Pull the main halyard tight again. Use short pieces of line thru the reef grommets to secure the excess mainsail to the boom. Undo the pigtail, and ease the mainsheet to resume sailing, under a reefed main. All this is accomplished from your cockpit. You could probably buy all of the parts for around $100. If you're sailing single handed, you'll appreciate the ease and safety factors.