OK once you have the fuel-cooling cowl and starter off.Just try and wiggle the starter with two screws drives to see if the flywheel will come off.Don't stand on the screw drivers and really force it,as if it is that tight then yes it will need a puller.Just give it a go it might be easy to come off,just don't force it as things then will break.If your spark plug lead is that short you will need to get the flywheel off to change the lead over.I use a harmonic balance kit to remove my flywheels if they are tight.
Like the pictured one.
[Linked Image]
Try that see how you go.

Here for a good time,not a long time.