Here's how I answered with a module example. May it be helpful to someone.
<?php
class UserNameLabel extends WireData implements Module{
public static function getModuleInfo() {
return array(
'title' => __('UserNameLabel', __FILE__), // Module Title
'version' => 100,
'summary' => __('Overwrite User Name Label', __FILE__), // Module Summary
'autoload' => true
);
}
public function init() {
// only add hook if on user pages
if(strpos($_SERVER['REQUEST_URI'],'/users/') !== FALSE )
$this->addHookAfter("Inputfield::render", $this, "changeLabel");
}
public function changeLabel($event){
$inputfield = $event->object;
// only if the right inputfield
if(!$inputfield instanceof InputfieldName ) return;
// overwrite the label
return $event->object = $inputfield->label = __("Username");
}
}













