If you have a Korg tuner, it has a little flat symbol on it. Hitting that will drop the target note down a half step. use it once to tune your E to Eb, twice to D, four times to C, etc.
Otherwise, you could tune up to E standard and then tune to your other frets.
When tuned to E standard, put your finger on the 3rd fret of the A string. This will be a C an octave higher than your target. Tune your lower string to an octave of that C (you should know when you hear it). Then you want to put your finger on the 5th fret of the D string. This will be a G. Tune your A string to an octave below this G. Move up to the 5th fret of the G string. This is C. Tune your D string down to this C.
Then, finally, hit the 5th fret harmonic of your new C string and the 7th fret harmonic of your G string. Let them both ring out. Tune your G string down until they're at the same pitch. Your new string will be tuned to F.
That's the hard way of doing things, but it works.
Or, if you have an Android phone, you can use the mobile app "G Strings lite". Or maybe Free instead of Lite. Just hit the "tune auto" button and it will act as a chromatic tuner using your phone's microphone.