just cut it straight off at the height you want. as long as there are leaves below where you are cutting it will re-leaf.

welcome to GoY too :o)

Hi, welcome to GoY, I would cut a few inches below the height you want it, so that when it regrows you can have the height you want, without having to cut into thicker wood, you can cut privet back as hard as you like, I've never known it not to releaf, Derek.