Pitch Bend entire song down one note?

my band is doing a reunion.
we are gonna be playing some old songs that were in Drop C guitar tuning…
a lot of our later songs are drop B so we are wanting to do those old C songs in B instead…
for relearning purposes we want to alter the recorded songs to that key.
what is the proper way to just pitch bend the whole song down one whole note in Cubase 5.
i think i know but i just wanted someone who knows better to hopefully give me a detailed tutorial