kantes on "The Morning After - Image Slider"

Hi,

I'm using a theme called 'the morning after' from Woothemes. I'm trying to convert my header image into an image slider using the meta slider lite plugin. I've managed to have it replace the header image with the code

"<?php
echo do_shortcode("[metaslider id=12]");
?>"

within the topbanner.php file but this sends the rest of the size crazy of course as it doesn't properly fit in with the code.

Any ideas on what I should be editing or where I should be inputting the code for it to work within the template?