Switching text is easy in timer.
1.HTML Markup
[code language=”html”]
<!– Slider –>
<section class="cd-intro">
<h1 class="wow fadeInUp animated cd-headline slide" data-wow-delay=".4s" >
<span>HI, MY NAME IS JONATHON & I AM A</span><br>
<span class="cd-words-wrapper">
<b class="is-visible">DESIGNER</b>
<b>DEVELOPER</b>
<b>FATHER</b>
</span>
</h1>
</section> <!– cd-intro –>
[/code]

put your texts under cd-words-wrapper class in b tag.

We have used this plugin from codyhouse. If you are interested for more follow this link – https://codyhouse.co/gem/css-animated-headlines/