Right. Well, first you'll want to sit or lie down comfortably. Then you'll want to think about your breathing--slow and steady from the gut. Try to focus on that for as long as you can. If you get distracted, just go back to thinking about it as soon as you catch yourself.
[If AR was a soldier from the Imperium, Cain might suggest reflecting on a particular verse or prayer, but for a weird xenos guy he'll just have to run with AR being calmed/bored to sleep.]