I have a 3 1/2 year old, her bio fahter is on her birth cirt. But I would like to take him off he is not in the pitcure. Does anyone know how I can do that?

You can not, he is the father, you can go to court and sue for full custody, you can get a new partner and see if your ex will allow the new partner to adopt.

And besides just taking a name off, what do you wish to prove or change, taking him off does not take away any right he may have as a father.
And it is not like he is not really the father legally.

So first taking him off does nothing even if you can do it, and second unless you can prove he is not the real father, and he is on the certificate he gets to stay on. ( and in some states even if he turns out not to be the real father, after a number of years, he can't even get off then)