Honestly, I don't know how the man attempted to perform the operation on his child. However, I imagine most North Americans fail to understand that the procedure commanded by god to Abraham was much simpler than the practice as it is known today.
Adults can modify their bodies as they wish. If a man wants to circumcise himself, then that is his business.
Genital modification on girls is against the law. Hopefully, someday boys and intersex children will enjoy the same equality of protection under law. Well, technically they already do except for cultural inertia favoring RIC, gender assignment bias, and general public apathy on the issue.