Replace text inside td using jQuery having td containing other elements

Using text nodes in jquery is a particularly delicate endeavour and most operations are made to skip them altogether.

Instead of going through the trouble of carefully avoiding the wrong nodes, why not just wrap whatever you need to replace inside a <span> for instance:

<td><span class="replaceme">8: Tap on APN and Enter <B>www</B>.</span></td>

Then:

$('.replaceme').html('Whatever <b>HTML</b> you want here.');