how to change column names in r

colnames(dataset) <- c('name1','name2',..)

my_data %>% 
  rename(
    sepal_length = Sepal.Length,
    sepal_width = Sepal.Width
    )

R> X <- data.frame(bad=1:3, worse=rnorm(3))
R> X
  bad     worse
1   1 -2.440467
2   2  1.320113
3   3 -0.306639
R> colnames(X) <- c("good", "better")
R> X
  good    better
1    1 -2.440467
2    2  1.320113
3    3 -0.306639

colnames(df)[colnames(df) == "name"] <- "new_name"

# df = dataframe
# old.var.name = The name you don't like anymore
# new.var.name = The name you want to get

names(df)[names(df) == 'old.var.name'] <- 'new.var.name'

names(df)[1] <- paste("newName")