Athiests how do you explain stories of  children remembering details of their past life?

The technical term is "Confabulation".

That's when a person genuinely believes something to be a true memory of their own experiences, when it's actually from their imagination or taken from a story.

It is a well known and well documented effect and can happen to anyone.

It's especially common in children and also people with memory problems, some types of mental illness or dementia.

 I dont have to - YOU explain it

Utter baloney.  That's how.  

Atheists, not Athiests.

The other stuff you wrote is dishonest nonsense and you know it.

It's called i-m-a-g-i-n-a-t-i-o-n. Children are highly subject to it. They also "remember" the time Rudolph the red-nosed reindeer visited them in their bedroom. What does this have to do with atheists?

born again Christian biologist

This question has nothing to do with atheism. 

Well, that's a new one on me!

By the time the story is included in a book, more details are added to make it sell better. 

No one can explain it, because there is NO such thing as a past life, it is written in God's word that you only live on earth once, after that, His judgment comes.

The Bible says that it is appointed for us to die only once, after which comes judgment (Hebrews 9:27).

Believing in reincarnation (even if it did exist) has nothing to do with religion.

''Religion'' says that you ''go to heaven''

NOT that you are ''born again on Earth as someone else''.