How to replace large amounts of text

My client changes her navigation every couple of weeks. I've tried using Notepad++ to replace large amounts of text, but it does not pick up all of the selected text. Textpad does the same.  

Here is the HTML navigation:

 

<!-- InstanceBeginEditable name="things" -->
<ul> 
  <li><a href="index.html" target="_self">Home</a></li> 
  <li><a href="mission.html">About Us</a> 
    <ul>
      <li><a href="mission.html" target="_self">Mission</a></li>       
	  <li><a href="vision.html" target="_self">Vision</a></li> 	  
      <li><a href="bio.html" target="_self">Ann Gibson, Intrepid Coach </a></li> 
	  <li><a href="cv.html" target="_self">Education &amp; Credentials</a></li> 
      <li><a href="how.html" target="_self">Ann's Approach</a></li> 
	  <li><a href="ourlogo.html" target="_self">Our Logo</a></li>
	  <li><a href="faqs.html" target="_self">FAQ's</a></li>	  
	  <li><a href="testimonials.html" target="_self">Testimonials</a></li>
	  <li><a href="tree.html" target="_self">The Giving Tree</a></li>
    </ul></li>
	<li><a href="shapeshifter.html"  target="_self">Free Stuff</a>
		<ul><li><a href="optin.html"  target="_self">Adventure Wellness eZine</a></li>
			<li><a href="/nook">The Nook (BLOG)</a></li>
			<li><a href="shapeshifter.html"  target="_self">Shape Shift Tele-series</a></li>
            <li><a href="thevision.html"  target="_self">Visionary Nutrition Tele-series</a></li>
		</ul></li>
	<li><a href="membership.html">Membership</a></li> 
	<li><a href="programs.html">Programs</a> 
		<ul><li><a href="gettingStarted.html" target="_self">Getting Started</a></li> 		 
			<li><a href="programs.html" target="self">All Programs</a></li>
			<li><a href="privateCoaching.html" target="_self">Private Coaching</a></li> 		 
			<li><a href="comingsoon.html" target="_self">Group Programs</a></li>
			<li><a href="membership.html">Membership Program</a></li>
			<li><a href="archive-calls.html"  target="_self">Media Library</a></li>
			<li><a href="payitforward.html" target="_self">"Pay it Forward" Trips</a></li>
			<li><a href="retreats.html"  target="_self">Retreats</a></li>
			<li><a href="events.html"  target="_self">Events</a></li>
			<li><a href="distance.html" target="_self">Distance Clients</a></li>
			<li><a href="specialOffers.html" target="_self">Special Offers &amp; Discounts</a></li> 	  		
			<li><a href="testimonials.html" target="_self">Testimonials</a></li>
		</ul></li>   
   <li><a href="/nook">The Nook (BLOG)</a></li> 
   <li><a href="marketPlace.html" target="_self">Marketplace</a>		
		<ul><li><a href="archive-calls.html"  target="_self">mp3 Recordings of Past Classes</a></li>                    
			<li><a href="comingsoon.html"  target="_self">Products</a></li>
			<li><a href="comingsoon.html"  target="_self">Partner Services</a></li>
		</ul></li>   		
   <li class="contact"><a href="contact.html" target="_self">Contact Us</a></li>
</ul>
<!-- InstanceEndEditable name="things" -->

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The replacement HTML navigation would be very similar - a few pages might no longer be inlcuded, but some others might take their place. I need to find an efficient way to replace this entire section of text with a new section of text. This type of support is costing me money because currently I'm opening every file & making the change manually. There's got to be a better way.

Any help would be appreciated.