Change avatar by mouse-over own avatar.

I'm trying to create a functionality like facebook's "Change Avatar". That when you hover your own avatar.. a button pops up.. with “change avatar”.

I've tried with this code in the member-header.php file and this works, but I have no idea how to add the image to the avatar with "Change Avatar" or in this case in dutch.. "Profielfoto Wijzigen"
Would be great if anybody of you experts knows how to add this.

<br />
<div id=&quot;item-header-avatar&quot;><br />
        <a>profile/change-avatar/&quot;><br />
       <?php bp_displayed_userr_avatar( 'type=full' ) ?><br />
       </a><br />
</div><!--#item-header-avatar-->