EMBARKING AND DISEMBARKING
Models can only voluntarily embark or disembark in the
Movement phase, and may not voluntarily both embark
and disembark in the same player turn.

Independent characters embarking and disembarking
If an independent character (or even more than one)
and a unit are both embarked in the same vehicle, they
are automatically joined, just as if the character was
within 2" of the unit. If either an independent
character or a unit is already in a vehicle, the other may
join them by embarking too (assuming, of course, that
there is enough space left).

Disembarking
The unit and the independent characters may, in a later
Movement phase, disembark together as a single unit.
They can also disembark separately by either the unit or
the characters disembarking while the others remain
onboard, or even disembarking at the same time using
different access points (but they must end their move
more than 2" away from each other). If the vehicle has
yet to move, both unit and characters can disembark
together and in coherency, but then the characters can
leave the unit as they move, as normal.