@Shayla W if you want to disable all styles, you can do it like so: http://jsfiddle.net/sanford/9wvf0zjz/show/
To be clear, this isn't changing the markup,
just disabling the CSS rules. In other words, if Marketo wraps a BUTTON in a SPAN, it's going to stay that way in the DOM. However you'll be able to style the markup any way you like.