How to make adult size knitting pattern to kids size

I am trying to knit leg warmers for my 8 year old daughter. But the pattern I found is for adult women. It has cable pattern in it. How can I resize it? Thank you ahead, I know I can count on this website!

It helps if you have a link to the pattern, or provide a little more information. What yarn, what size needles, etc…

http://knitty.com/ISSUEspring08/PATTmosey.html

That is the pattern for it.

Thanks, that makes it a little easier to advise you.

The original pattern is written for worsted weight on size 7 needles. You can go down to a fingering or sport weight on size 4 or 5 and use one of the sizes given. Figure out your sts per inch and divide into the st numbers given to see which one is closer to the measurement you want.