If he's already crowing I'm guessing he's also way past the point of sterilizing (caponizing). You can do a search on the forums if you want, though I will say it's not a pretty procedure as the testicles are inside the bird's abdomen and past a certain point, they're simply too large to safely remove.
I'm really impressed you're willing to move to try and keep this bird, that's a lot of dedication. Best of luck!
I'm really impressed you're willing to move to try and keep this bird, that's a lot of dedication. Best of luck!