In this case, neither of those worked.Probably because it is a plugin. Unless the author of the plugin has provided specific hooks to change the bits you want to change then you are going to have to change the class file directly.
It's just a matter of changing this one thing that has me a bit baffled.This is what I would do - but I am not a fan of WP and hunting around trying to find some functionality some other person may have written that approximates my need while checking for security holes etc etc just seems like a big waste of time to me. If licensing permits copy the plugin change it to do what you want - change the plugin name and install it as a new plugin.
$this->add_style( 'width', '60px', 'name' );
to
$this->add_style( 'width', '100px', 'name' );
The file in the plugin that I need to override begins with this:
Open in new window
The file is quite fairly long - around 200 lines - but there are several places I where needed to edit it to get it to work the way I want, so overriding the whole file is ideal, but there may be a simpler way to override the class or the function.
With other plugins, I was able to either copy the file I wanted to override into my child theme with the same folder structure. Or I was able to copy just the function into my child theme functions.php. In this case, neither of those worked.