Cringle Grommet
If you have a hole with a brass/metal ring on the sail - usually in pairs this is a cringle - a reef point; if you have another set it would be your second reef point. They are usually connected to a cringle hook, but you can use line to secure them as you lower the sail. The sail ususlly has short reefing lines to tie off the bunched sail you lowered. The load is taken on the cringles. Lower the sail hook or tie off the cringles, put load on this by trying to raise the sail, then tie off the reefing lines between the cringles - use a square knot.
Try it out on a not so windy day. On winds 15 kts + consider reefing before you leave the dock.