The flowers will open by themselves and drop pollen.
Pollen can be used as soon as it drops.
You can also, after the first few flowers open, cut the stalks off, hang them upside down in a paper bag and collect pollen that way.
After being cut off, the male flowers will "after ripen" and open and drop pollen once mature enough after harvest.
This method makes containing the pollen extra simple..........wait 4-5 days after placing them in the bag, then open the bag carefully and there should be a pile of pollen at the bottom of the bag.
Apply the pollen with a small paint brush or small, very fine make up brush..........do not use Q-tips, the pollen will stick to them and not transfer to the female flowers.
If you only get a small amount of pollen, it can be mixed with fine flour at up to 80% flour and 20% pollen and you will still get 100% fertilization.
I have been doing this for many years now and it works perfectly.
Pollinate the freshest, newest female calyxes with the whitest and juiciest pistils only, at the base of the buds....... it will take 4-6 weeks for the seeds to fully mature.
You will know the seeds are mature once the calyx dries up, splits open and then you will be able to see a shiny dark brown seed inside the calyx.
Waiting patiently for the seeds may seem difficult, the flowers will be well over ripe and generally unsmokable, but seed production only happens this way.