Modificar botones del editor Summernote

http://summernote.org/deep-dive/

Ejemplo

$('.summernote').summernote({
            height: 350,
            minHeight: null,
            maxHeight: null,
            focus: false,
            toolbar: [
                ['codeview', ['codeview']],
                ['fullscreen', ['fullscreen']],
                ['bold', ['bold']],
                ['underline', ['underline']]
            ]
        });