How to customise the default search widget in Upfront


Id it possible to edit the search box that comes up by default in the drag and drop options (in Upfront) of the Spirit theme? I would like to be able to edit the text inside the bar and also to remove the separate "Search" button, similar to the widget that was on the original home page before i began editing the theme. Please let me know how to get that initial search bar back or edit this one to resemble it?