Problem with CSS

Hi, I am using your plugin in my website, but it conflicts with other plugin called Visual Composer css and with my current theme css (made responsive design).
How can I edit manually the css for each button color? and for other things like “label”?
Or can you use a diffent name for the class in buttons? I saw that a lot of plugins use the same class names in their css.

Thanks

https://www.ads-software.com/extend/plugins/plumba/