Magento

Hello.

I need to make some changes to the layout of the pdf printouts.
I want to do this by overloading the original classes with a custom module. I followed the wiki guide for custom modules but my customizations are not loaded, and the pdf files still have the default layout.

I think my problem is the configuration file in local/MyCorp/Sales/etc/config.xml

I do not know what I need to put in there to tell Magento that it should load my customized files instead of the default classes.

Any help appreciated.