Very easy..
Get a small block and 1/4 inch diameter polyester braided line at the HW store. Tie the block at a convenient location near the base of the forestay using a small piece of line, and then run one end of the down haul line through it and tie it off just above your jib halyard clasp (that attaches to the head of the sail). Feed the other end of the down haul line back to the cockpit. On my H260, I use a fairlead attached to the forward stancion on the port side, although you might get away with just running it through the stancion base supports.I tied off the bitter end of the downhaul on the rear stancion (port side) so it is just a little snug when the jib is raised.When the jib comes down, you pull in on the down haul as you ease the halyard. Once the jib is down, I tie off the downhaul on the port side jib cleat to keep it down. Also, pull one of the jib sheets tight (I usually use the port side) to keep the foot of the sail from going over board.I also have a sail tie on the lifeline forward to tie off the sail when I get a chance to get up there. Keeps it a little neater and the sail controlled on the deck.Fair winds,Tom