How to change banner image & content

We used fixed image in banner of index-text.html file. Code is given below

<header class="header th-fullpage" data-parallax="scroll" data-image-src="img/header\_bg/banner-img.jpg">
 <div class="section">
 <div class="container">
 <div class="row">
 …………  
 <div class="col-md-12">
 <h1 class="text-center">We’re Creative <br>
 We Ensure Quality Design</h1>
 …………..  
 </div>
 </div><!– /.row End –>
 </div>
 </div>
</header>

1. Change contents from h1 tag.

2. Change image from data-image-src.