Is it possible to "help" someone out of their physical body?
Is it more difficult to try to AP while sleeping with someone else in the bed?
Nice to see you've regained some interest in the mystic.
The answer is Yes, it's possible to help someone out. If you go that route your best bet is to ask a higher spirit to help you out; and do this every night before you fall asleep.
From what I know it takes someone already out-of-body who then goes to the person (who is asleep) and tries to interact with their astral body. The person who is sleeping will usually see the APer in the form of a dream, the APer will try to interact with the person and tell them to leave their body.
At this point it varies, sometimes the person is able to "wake up" and leave the dream, other times they're not.
Other ways that would fit with your question are asking spirit guides, spirits, higher beings, your higher self, etc for help while in a meditative state before sleeping.
It's not more difficult to AP with someone near you, unless they're tossing about, snoring, or otherwise disturbing you. However, If you're focusing on the person, noticing, or thinking about them maybe it would be best to do it alone.
I don't think you're going to get results (help from another APer) unless they either know you well in real life or are around your physical body at the time you want out.
My advice to you is to change the method you're using to get out of yer body. Try a new one every week if you're not getting results.
Personally, I think just trying to watch yourself fall asleep works best (at least for me). You think of some scenario which then starts to become a dream, and if you catch it just right you'll pick up on vibrations if nothing else.
Anyway good luck