@abhik21 That is not a solution to the posted problem. Obviously Dcleeds does not want to use a plugin to get this done.
Create a child theme (which is best practise when changing themes). There’s plenty of information on how to do that. Put the files that you need in there, so in this case at least header.php
(Or edit header.php directly in the original theme directory, but be prepared to do this everytime when the theme is updated, if you haven’t created a child theme).
Upload the logo in your (Child-)theme folder. Edit the header.php so that you remove the stuff between the
<div class="site-branding">
REMOVE STUFF HERE
</div><!-- .site-branding -->
Now add the logo in there with a traditional <img> tag. I’ll give an example here, where of course you have to put in your own details:
<div class="site-branding">
<img src="<?php echo get_template_directory_uri(); ?>-child/logo.png" width="250px" height="90px" alt="Some alt text here">
</div><!-- .site-branding -->
In this case I’ve appended the theme URI with “-child” to point to my child theme which (in my case) is the name of the main theme with “-child” appended to it. Add your own widths and heights, your own alt text and the name of your own logo and you should be set.
By all means explore the creation of a child theme to avoid problems with future updates of your theme.