If you wanted to tune your strings based on the E, then you put your finger on the fifth fret (the A), and tune it the string above that so they match. Then do the same thing with the D. On the G, you put your finger on the 4th fret for B, and then on the B put your finger on the 5th fret again for E.
If you want a REAL tuning, you're gonna need a tuner.
If you were even asking about tuning at all...