Could you refer me to a resource for information on castrating roosters?

The Stromberg catalog has tools, information, and a booklet in a complete kit. You can contact them via the link on this site.

I urge people not to go to the trouble, however, because with today's Cornish X genetics, it's easy to produce a very large and tender bird without surgery. Feeding them to 10 or 12 weeks will give you a capon-sized bird much more easily. We feed ours to 8 weeks for roasters that dress out to nearly five pounds. Good luck.