It's not a bad job.
Tank and seat off.
Fairing off, belly pan, airbox, carbs and plastic plate underneath.
Drain coolant, and old oil (makes the old lump lighter).
Footrests, gear lever and rear brake lever/gubbins off.
Exhaust off and disconnect chain, usually easiest is to remove rear wheel, chain then slack enough to take off of front sprocket.
Remove clutch lever, and then take off sprocket cover.
Now take off water pump, rads. and thermostat housing, and all the pipes.
Disconnect any wires, coils, sensor leads etc.
Now the bike has to be balanced ready for the engine mounts to be undone, and that's the tricky bit.
If you just support the bike with a jack under the sump it's too unsteady, and you can easily drop it while wrenching on a socket or spanner.
So either tie its handlebars to something substantial on either side, or clamp the front wheel between two blocks of wood bolted to a large wooden plate.
If you can secure the front wheel then a jack underneath will lift the rear end off the ground and leave the bike secure.
Now you need to take off the swingarm and shock linkages, and then undo the engine mounting bolts.
These are sometimes a complete m/wombles, and you might need to hire or borrow the correct castellated box spanners.
The, leaving the engine on its jack, lift the back end of the bike off the engine.
Swing the new engine in the same place, and lower the bike down onto it.
Then the same in reverse order.
Make sure you put chain on before footrests and exhaust.
Go on then, have I missed anything?

It's not falling off, it's an upgrade opportunity.