Advise....
Rather than remove or replace
With the 1st code wrap it around with
PHP Code:
<vb:comment> </vb:comment>
So when done it will look like
PHP Code:
<vb:comment> <h2 class="forumtitle"><a href="{vb:link forum, {vb:raw forum}}">{vb:raw forum.title}</a></h2> </vb:comment>
Then proceed to add your code below it
Next do the same thing you did for the 1st one. So when done it will look like
PHP Code:
<vb:comment> <vb:if condition="$show['forumdescription']"><p class="forumdescription">{vb:raw forum.description}</p></vb:if> </vb:comment>
This will help you during an upgrade and not have to completely revert everything.