How to tune my guitar a semitone down usisng the CA-1 Tuner

[yesman]

Hi

I recently purchased a CA-1 Guitar tuner and was just looking for some help / advice on how to use it.

Basically, I would like to know how to use it to tune my guitar a semitone lower ( I am trying to learn a new song which says tune down a semitone)

I read thru the Owners Manuel but to a layman like myself I could not get how to do this.

Any advice in simple terms would be greatly welcome !!!

Thanks

Alan