tune down half step?

I understand that tuning down a half step does = produces flats or sharps by playing normal notes however how do u actual tune down half a step?

I'm only a beginner but I THINK you tune the low E to D#(or E flat) and you can tune the rest of the guitar to that. Get it? You know, fifth fret. Somebody help us out here. I'm really glad I could help!

sure.if yer tuned now, just tune yer A string to yer
E string 4th fret then tune yer E down so its in tune
with yer A...then tune the D to the A etc...yer just
takin each string down one note is all.

Adding to the previous comment, to do this you need to firstly make sure that the guitar is in tune anyway.

But, if you have a pretty good ear for hearing if the two tones are correctly matched, use software called Power Tab editor. Download this from cnet.downloads.com, or search for it from Google.com

Start it up, and setup your score so the guitar is tuned down half a step. Then make it play each string open so you hear what it should sound like. Tune to this, and there you have it.

Power Tab has every possible tuning for the guitar, bass, double bass, cello, sax, banjo, acordian you name it...
I hope dis helps a little