Right well start off with your guitar in drop d, then........
Tune the low (dropped) D string down so that the 8th fret on that string becomes an A
Next tune the A string down until the 6th fret matches a D
Then tune the D string so that the 6th fret matches the G string
Now tune the G string until the 5th fret matches the B string
Then B string tuned down so 6th fret matches the e string
Then again on high e (being the thinnest string) tune it so that the 6th fret becomes an A
Hope this helps , I use this when tuning to drop db with my tuner which is basically the same as yours.
(hopefully thats all correct)