I had to respond as I had wanted to change mine too. I found out according to the forum information that it can't be done at this time.
When I first wanted to ask a question every user name I tried to enter came back as already taken so I just typed in this one, not knowing I would forever be stuck with it. Alas, though it does seem I forever will need help.
I also had to respond as you commented on my chicks as being pullets. Boy, that would be awesome, and yet funny as like I posted someone was going to trade a black orpington pullet for one of the lavender cockerels. If you do get a different response on changing the user name, let me know! Thanks!