Here's a picture by picture takedown, not as good as a video but it should do well enough.
Again if you want to try and repair it figure out how much your time is worth. Chances are it's not worth it to repair it and instead just use it as a parts gun or something.
PS: Don't spoil your kid, honestly. It's OK once in a while, my parents did that but I have to purchase my own car and stuff like that. I know the true value of work/money and try my best to be careful with my stuff.