To tune your guitar to drop B tune the low string to B follow the following steps: tune the second string to F#2 at 92.50Hz, tune the third string to B2 at 123.47Hz, tune the fourth string to E3 at 164.81Hz, tune the fifth string to G#3 at 207.65Hz and lastly tune the sixth string to C#4 at 2777.81 Hz.
3 Additional Answers
To tune your guitar to drop B, get a chromatic tuner. The notes, starting from the bottom, are B, F sharp, b, E, G sharp, C sharp. This is a difficult key to tune to because it is such a low key. You can find more information here: www.fretjam.com
You can tune your guitar to drop B by tuning the lowest string to B. You can do this easily by using a guitar tuner like the one located at tunemybass.
In order to tune your guitar to drop the b you are goign to have to hook it up to a chromatic tuner and let it do the work automatically for you. This is the easiest and most efficient way.