One way to get out of it is to tell yourself that you're actually awake and that you aren't being harmed.
I don't think this works...
From what I remember, it's not some psychological thing. Your arms and legs become paralyzed by REM Atonia (Can't remember if 'Atonia' is the right word...). It's where your arms and legs aren't stimulated during REM sleep, which makes them immobile.
Sleep paralysis happens when you awake too abruptly from REM sleep. You're awake, but not completely, and some REM effects last for a few minutes.
So you can't just convince yourself out of that kind of thing, though I could be mistaken.
