[Plugin: Basic Google Maps Placemarks] Changing default icon

I use a WP theme, instead of a custom theme, so I don’t want to edit the functions.php file as my changes will be washed away when I updrade the theme or change the theme.

Can you add this functionality directly to the plugin’s admin/config?

http://ww.wp.xz.cn/extend/plugins/basic-google-maps-placemarks/