2011 Nissan Sentra 2.0 engine removal

2011 Nissan Sentra SR 2.0 liter 4 cylinder. Trying to
remove the engine and trans as a unit to do timing chains.
Not enough room to wrestle the timing cover on and off
and actually have it seal trying to do timing with the engine
in the car. Tried a million different things. Is it even
possible to pull the engine and trans as a unit through the
top or do I HAVE to drop the subframe? Working in my
garage with an engine hoist, several floor jacks and
jackstands. Any help would be appreciated. I'm about
ready to burn this thing down and walk away.