BKSS -
You're free to move it out of state *yourself*.
That is, put it in a locked case and drive outta Kalif. (I'd carry paperwork though, in case of traffic stop - see below). There's no requirement to turn it in upon death or do any crazy thing that Kalif wants once it's outta state.
However, if you use a shipper (UPS, FedEx, etc.) to ship the AW outta state - for whatever reason, storage, repair, 'smithing - you must use the services of a registered Assault Weapons Dealer. An ordinary Kalif. FFL will not suffice for this.
You are free to sell it in a 'free' state. However, you prob should go thru an FFL even if face-to-face paperwork-free private-party transactions are legal in said free state, because you are a out-of-state resident, and there are some ATF rules covering this. But I think that applies to *any* gun in this situation - Kalif's AW status has no bearing on situation outside of Kalif, it's just a gun.
You're also free to bring your AW in & out of Kalif (if stored/transported appropriately). Remember, you can't just 'drive around' in Kalif w/an AW in your trunk; you have to have specific authorized destinations in mind when transporting said AW - going home, to target range, to (AW-certified 'smith), to friend's (who'd like to see your latest mods to your new toy), outta state... Having a couple of changes of clothes (shirts, sox, undies, extra pants, a shave kit - not just an old pair of dungarees or painter's coveralls) neatly packed in a bag in your vehicle would tend to indicate an intention of substantial travel and support your out of state travel claim ;-)
I always carry multiple *copies* of my reg paperwork with me just in case cop's radio/datalink is down during a traffic stop.
Keep one copy in glove box with car reg & insurance papers; keep reduced copies in buttstock of each AR and in carry case.