cd /usr/local/share/nagios/ssi

ee common-header.ssi

<br>

<strong>

Your Custom Header | Custom Link 1 | Custom Link 2

</strong>

<br>

<hr>

<br>

Save this file.

ee common-footer.ssi

<br>

<strong>

Your Custom Footer | Custom Link 1 | Custom Link 2

</strong>

<br>

Naturally you would replace my sample code with your own HTML.

Nagios will automatically include your newly created files in it's display.