drop existing table in the database and create a new table in the same database in sqlite android

designing an application in which I require to drop the tables present in my applications database when the user clicks a button and then again call the onCreate(); method to create new table in the same database but with different number or names of the columns. data loss is not an issue when I drop the tables. I have a little idea that onUpgrade(); method could be used for this but how can someone please explain . thank you.