Morning Sylvia, I usually let them dry naturally outside in the sun and then the seeds will fall out with a good shake, I also leave some of the flower heads on the plant for the Finches to eat during the winter 😀👍🏼😀
Here, we cut the sunflower head off and set it in a dry sunny location with lots of air flow. Big heads will take longer to cure. After a couple of weeks, the seeds should turn almost black. Take your thumb and briskly rub over an outer section. If the seeds pop out easily, they're finished😊
Thank you @gjones @sieveheadsarah i think my main concern is that the weather is quite damp now with little opportunity for them to dry out or bake. I wondered whether i was better cutting the heads off and putting them in an airy under cover shed?