Tune down the bass e string so that the seventh fret note is an a, and it is the same note as the next string down. Then, play the fifth fret note on the e string (a G now), and tune the A string to match that. Then, tune as normal with the other strings (ie. to the fifth fret of the one above it, except to the fourth with the b string).
"Dozens of people spontaneously combust each year, it's just not that widely reported".