legend modify with ggplot code example

Example 1: labs fill ggplot2

p <- ggplot(df, aes(x=rating, fill=cond)) + 
           geom_density(alpha=.3) + 
           xlab("NEW RATING TITLE") + 
           ylab("NEW DENSITY TITLE")
p <- p + guides(fill=guide_legend(title="New Legend Title"))

Example 2: remove ggplot legend

bp + theme(legend.position="none")