Allow for Photo Upload in User Info Section

Currently I am using WP-About-Author Plugin to put user info below Author Posts.
Most of our authors will not have a gravitar so I have customized the plugin to insert an uploaded photo for certain users.

function get_uploaded_avatar() {

if (get_the_author_meta('last_name') == 'LastName') {
        $avatar = "<img alt='author-image'src='http://www.location.com'/image.jpg>";
   } elseif (get_the_author_meta('last_name') == 'LastName'){
       $avatar = "<img alt='author-image'src='http://www.location.com'/image.jpg>";
    }else { $avatar = get_avatar(get_the_author_meta('email'), '100'); }
   return $avatar;
}

Right now I want to allow Authors the option to upload a photo in the edit user section and use that photo inside of this plugin.
How can I add the option for users to upload a photo inside Edit Users Page?
How can I tie that photo to each user?