I'm gonna have to ask people to find the song first, because it's the only example I have. It's Undertow by Tool.

Anyways, the guitar riff immediately before the chorus sounds just like the chorus, but a little lower. Before the chorus, every note is just used by playing one string, but during the chorus, notes use 3 strings. So, my question is, how would I go about transposing a riff so that I can do the same thing, meaning go from just playing single notes to playing three-string notes.
"Did you check the bathroom, the bathtub? She sleeps there sometimes. Water cleanses, you know. Washes dirt away, makes new. Maybe she swam away."