Change askbug header logo

I bought the askbug theme, i just want to change the red askbug text that shows on the left part of the header for my own text. Anybody can help me?

<div class="site-nav-logo site-nav-flexi">
      <a class="logo" href="<?php echo esc_url( home_url( '/' ) ); ?>" title="<?php echo esc_attr( get_bloginfo( 'name', 'display' ) ); ?>" rel="home">
       <?php if ( has_custom_logo() ) : $logo = wp_get_attachment_image_src( get_theme_mod( 'custom_logo' ) , 'full' ); ?>
        <img src="<?php echo esc_url( $logo[0] ); ?>" alt="<?php echo get_bloginfo( 'name' ); ?>" width="<?php echo $logo[1]; ?>" height="<?php echo $logo[2]; ?>">
       <?php elseif ( ! empty( get_theme_mod( 'ab_logo' ) ) ) : ?>
        <img src="<?php echo get_theme_mod( 'ab_logo' ); ?>" />
       <?php else : ?>
        <i class="apicon-logo"></i>
       <?php endif; ?>
      </a>
     </div>