add banner to plugin page

I recently created a WordPress plugin and used SmartGit to commit the code to the WordPress repository. No problem.

I want to add a banner to my plugin page. From the WordPress documentation, below, is how this should be done. I’m having trouble with #2. When I update with SmartGIT, it seems only the trunk files are updated. I can’t seem to figure out how to update any other directory.

Any thoughts? I’m brand new to GIT/subversion/SmartGit.

thanks

To Add a Plugin Header Image:

1) Make a 772×250 pixel jpeg or png. (No animated GIFs. ?? )
2) Check it in to your plugin’s SVN directory with the path assets/banner-772×250.(jpg|png) and assets/banner-1544×500.(jpg|png). Note that the assets directory is added to your plugin’s root directory, not trunk.