customize search by ID, Nickname and Tag

I want to set the search members page up so it will serach by nickname, then email, then kkeyword in the 3 boxes at the top.  How do I customize this?

You cant search in the front end by email.

Shouldn't I be able to edit the search.php, search.css and maybe a few other things to customize this?  There must be some way.  Thanks everyone in advance!