pick somebody's brains

pick (one's) brain(s)

To ask one questions in order to obtain detailed information or advice. You should pick John's brain sometime. He knows all about car engines. I've just started playing professionally, and I'd love to pick your brains for any tips you might have.
See also: pick

pick somebody’s ˈbrains

(informal) ask somebody who knows a lot about a particular subject for information or ideas: I need some help with this project. Can I pick your brains?
See also: brain, pick