<script src="http://code.jquery.com/jquery-1.6.2.min.js"></script>

<style>
  .step { display: none; }
  .step-one .step.one { display: block; }
  .step-two .step.two { display: block; }
</style>

<div id="stepContainer" class="step-one">
  <div class="step one"><a href="#" id="showStep2">Show Step 2</a></div>
  <div class="step two">Welcome to Step 2</div>
</div>

<script>
  $('a#showStep2').live('click', function (event) {
    $('#stepContainer').addClass('step-two').removeClass('step-one')
  });
</script>