How to ajaxed this??!

I want to make “read the rest of this entry” link become fancy and interesting.

I found this code somewhere when i’m googling:

<script type="text/javascript"
    src="https://ajax.microsoft.com/ajax/jquery/jquery-1.4.4.min.js">
    </script> <-- (I think this is unnecessary because wordpress already has jquery in it's directory, isn't it?) -->
    <script type="text/javascript"
    src="https://plugins.learningjquery.com/expander/jquery.expander.js">
    </script>
    <script type="text/javascript">
        $(function () {
            $('div.readmore').expander({
                slicePoint: 200,
                expandText: 'Click Here to Read More',
                userCollapseText: 'Hide Text'
            });
        });
    </script>

and this:
<script src="https://ajax.microsoft.com/ajax/jquery/jquery-1.4.2.js" type="text/javascript"></script> <-- (is this required?)-->
        <script type="text/javascript">
            $(document).ready(function() {
                $(".message").hide();
                $("span.readmore").click(function(){
                    $(".message").show("slow");
                    $(this).hide();
                });
            });
        </script>

But i don't know where these code to be inserted??!

Below are the codes that i found in my theme directory that produce "read the rest of this entry" link.
In my archive.php
<div class="entry">
      <?php the_content() ?>
    </div>

In my index.php
<div class="entry">
      <?php the_content('Read the rest of this entry →'); ?>
    </div>

In my page.php
<div class="entry">
      <?php the_content('<p class="serif">Read the rest of this page ?</p>'); ?>
      <?php wp_link_pages(array('before' => '<p><strong>Pages:</strong> ', 'after' => '</p>', 'next_or_number' => 'number')); ?>
    </div>

In my single.php
<div class="entry">
      <?php the_content('<p class="serif">Read the rest of this entry →</p>'); ?>
      <?php wp_link_pages(array('before' => '<p><strong>Pages:</strong> ', 'after' => '</p>', 'next_or_number' => 'number')); ?>
    </div>

Hmm, anyone knows? I don’t know how to replace the above codes with those jquery.