How to remove Flywheel on Jet ski?

Flywheel removal on Kawasaki Jet ski 1100 STX model.

I need  to remove flywheel to replace the bindex?

There is a nut on the Flywheel assembly that has to be removed to loosen the flywheel.
To remove the Nut use Using a 9/16 inch socket.
The bolt is metric.

ENGINE IS NOT GETTING STILL TO REMOVE THE FLYWHEEL?

To get the engine still,so that you can remove the flywheel.
You can remove the spark plug from the front cylinder, look down in the hole and spin the engine over by hand, get the piston to top dead center, turn the engine until the piston drops down about 2 inches, then feed some rope into the hole. The rope will stop the piston from completing its stroke and lock the engine for you.
And you can now easily loosen the nut to remove the flywheel.

THE NUT IS VERY TIGHT TO BE REMOVED.ALSO THERE IS VERY LESS ROOM?

In most cases the nut gets easily removed.But if in your case the nut is got very tight due to getting very old and rusted.Then to apply power on the socket to loosen the nut you need more space.
So in that case, sliding the gas tank forward will allow you better access. I usually dont find much corrosion on that bolt, the compartment is sealed, or is supposed to be.But still if the rust is not letting the bolt to move ,then you can use rust remover spray on the nut.A spray like WD-40 helps in such cases.This spray will dilute the rust in few minutes and you can easily remove the nut by wrench. Make sure you have the proper size socket and use a long breaker bar.

This details will help.
Thanks.