A couple of months ago, I cut off the sunflower heads, wrapped them in cheesecloth and hung them up in the garage to dry.
Today I unwrapped them and picked the seeds out. It makes for very sore fingertips. I used a glove, for part of the time, but it's hard to do stuff with gloves on.
Got 2.2 pounds of seeds. I'm not sure what to do with them now. I'll have to google it. I ate a few and they were quite good.