You purchased it as a 'meatie' it's not like it was going or will have a fairy tale life even under the best conditions... I suspect unless you devote a ton of time to babysitting it and caring for it all day, it's not going to really enjoy it's next 8 weeks of life, just my opinion...
Painless and works well for small birds (and even adults if you up size) if you can't bring yourself to snap/cut the neck...
http://www.alysion.org/euthanasia/making-the-euthanasia-chamber.html