We've started getting serious with apologising with our 2 year old.
So far he appears to be a hard nut. 
Today he flatly refused to say sorry for ages, and I was getting bloody worried by the time he eventually mumbled it as I was way out of my depth.
So for future - any tips for making it easier for them to say it? What do you do if they refuse to say it? How long do you press the point when they're only 2?