If you can get sufficient leverage then pure torque will do it, but you may need a breaker bar a metre long and maybe a lump hammer to assist by giving the back of the socket a tap when it's loaded up. Use a length of wood through the rear wheel to lock it against the swingarm.
The engine will probably be getting on for half the mass of the bike. Unless you're unfeasibly strong and dexterous it's a 2-person job to remove, refitting is easier with three.

RTFM will really help, do that first....