I assume you mean echinacea. the brown cone of the flower will in time form seeds. You will know when they are ripe when you gently rub your fingernail over the cone. the brown/black seeds [1-2mm in size] will fall out. save them in a paper bag or small paper envelop until the spring in a cool dry place.
then start them off in spring in a 3" pot of compost. when they have 4 leaves prick them out and plant on into individual plants. plant out in flowering position late May onwards. they should flower the following year. well they do for me anyway.
hope this helps.

Very enlightening thank you very much
Brian

Do I chop them down at the end of flowering.
Brian

yes you can to 'tidy up', though I leave them until spring as the goldfinches like the seeds.