Last time I reefed the mainsail, I jammed the reefing line and had to take out the stopper knot to unjam it. Of course I forgot to put the stopper knot back in so the next time I sailed, the reefing line came out the end of the boom. How do I thread it back thro the boom to the mast? I sail a Hunter 34 (1986). I've only had it for 3 weeks now so am unfamiliar with everything.