Sub Heading Plug in with Montezuma Template

Hi there,

I have tried to implement this Plug in in my Blog with the Montezuma template. It will enable the feature to set an optional sub header for each site and/or article in Wordpress.
http://wordpress.org/extend/plugins/subheading/

But i'm not able to include the necessary PHP code in the template.

I also tried an other option via "built in" feature with Wordpress, but i also have to set an new function in the PHP code of every site or article template. It also don't work.

Can someone help me with easy words, how to implement this plug in in this template?


Many thanks for your help!