JSFiddle - React, Tailwind, and code Playground

HTML

<script src="//netdna.bootstrapcdn.com/twitter-bootstrap/2.3.2/js/bootstrap.min.js"></script>
<link rel="stylesheet" href="//netdna.bootstrapcdn.com/twitter-bootstrap/2.3.2/css/bootstrap-combined.min.css">
<script src="//cdn.jsdelivr.net/bootstrap.filestyle/1.1.0/js/bootstrap-filestyle.js"></script>
<a href="#changeAccountsSourceModal" role="button" class="btn" data-toggle="modal">Launch modal</a>

<div id="changeAccountsSourceModal" class="modal hide fade" tabindex="-1" role="dialog" aria-labelledby="myModalLabel" aria-hidden="true">
      <div class="modal-header">
        <button type="button" class="close" data-dismiss="modal" aria-hidden="true">&times;</button>
        <h3>Add account</h3>
      </div>
      <div class="modal-body">
          <ul class="nav nav-tabs">
            <li class="active"> <a href="#" id="chooseImap" data-toggle="tab">IMAP</a></li>
            <li><a href="#" id="chooseFile" data-toggle="tab">File</a></li>
          </ul>
        <form class="form-horizontal">
  <div class="control-group form-group">
    <label class="control-label" for="inputPassword">Password</label>
    <div class="controls">
      <input type="password" id="inputPassword" class="form-control" name="passwordI">
    </div>
      </div>

</form>
      <div class="modal-footer">
        <button class="btn" data-dismiss="modal" aria-hidden="true">Cancel</button>
        <button class="btn btn-primary" id="importB">Add</button>
      </div>
    </div>

JavaScript

var formContent = "";
    
            $("#chooseFile").on("click",function(){
                
                formContent = $("#changeAccountsSourceModal .form-horizontal").get()[0].outerHTML;
            
                $("#changeAccountsSourceModal .form-horizontal").replaceWith("<input type=\"file\" class=\"filestyle\" data-input=\"true\" data-buttonText=\"Choose address\">");
                $("#changeAccountsSourceModal :file").filestyle();
            
            });
            
            $("#chooseImap").on("click",function(){
            
                $("#changeAccountsSourceModal .modal-body div").remove();
                $("#changeAccountsSourceModal .modal-body").append(formContent);
            
            });