Nextend Social Login - HTML markup of the buttons and container

nsl-default-buttons-with-container.html

<div class="nsl-container nsl-container-block nsl-container-login-layout-below-separator" style="display: block;">
   <a href="***?loginSocial=facebook" rel="nofollow" aria-label="Continue with <b>Facebook</b>" data-plugin="nsl" data-action="connect" data-provider="facebook">
      <span class="nsl-button nsl-button-default nsl-button-facebook" style="background-color:#4267b2;">
         <svg xmlns="http://www.w3.org/2000/svg">
            <path fill="#fff"></path>
         </svg>
         <span>Continue with <b>Facebook</b></span>
      </span>
   </a>
   <a href="***?loginSocial=google" rel="nofollow" aria-label="Continue with <b>Google</b>" data-plugin="nsl" data-action="connect" data-provider="google">
      <span class="nsl-button nsl-button-default nsl-button-google" style="background-color:#dc4e41;">
         <svg xmlns="http://www.w3.org/2000/svg">
            <path fill="#fff"></path>
         </svg>
         <span>Continue with <b>Google</b></span>
      </span>
   </a>
   <a href="***?loginSocial=twitter" rel="nofollow" aria-label="Continue with <b>Twitter</b>" data-plugin="nsl" data-action="connect" data-provider="twitter">
      <span class="nsl-button nsl-button-default nsl-button-twitter" style="background-color:#4ab3f4;">
         <svg xmlns="http://www.w3.org/2000/svg">
            <path fill="#fff"></path>
         </svg>
         <span>Continue with <b>Twitter</b></span>
      </span>
   </a>
   <a href="***?loginSocial=linkedin" rel="nofollow" aria-label="Continue with <b>LinkedIn</b>" data-plugin="nsl" data-action="connect" data-provider="linkedin">
      <span class="nsl-button nsl-button-default nsl-button-linkedin" style="background-color:#0074b3;">
         <svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24">
            <path fill="#fff"></path>
         </svg>
         <span>Continue with <b>LinkedIn</b></span>
      </span>
   </a>
</div>

how to change default markup in theme integration?