How to change registration text?

For some reason when you register it says you have to be thirteen and agree with rules and what not, but I have loadsa users who are eleven and twelve. Think there's even a ten year old.
And there's a lot of confusion over that, especially when later on you can change the birthdate to a lot younger than that.
If younger than 13 isn't allowed on this server then why is it possible to change it to younger than that? That's not my main question/problem.
I just want to change the text of registration, cause it's too confusing for my users.


edit: I know you can change the settings of the age changing, but I don't want to. i want people of any age to sign up without confusion.

You have to be 13 to even use Forumotion Service. It is set by the servers for this reason. I'm not sure why you can change it to lower in the profile when its set by the servers.

Ugh. This is a bit silly really.

I don't understand why let people change it to younger than that then.
I have a lot of teenage girls on my forum. My forum is for girls that age.

But can my forum be shut down because of it now? I mean it's the server's fault for letting people change their age then.
Will I be given a notice? Cause I want to move over to some other server then and give the girls a notice aswell.