Re: 1999 mercuty 200 saltwater series removal of flywheel
You need a flywheel puller that threads into the center of the flywheel, you then thread another bolt into the puller and when you tighten it down it pops the flywheel loose. I got mine from ebay for around $25, it doubles as a lifting ring and flywheel puller.
They are described as "universal" and it fit my 40hp Mercury but your engine may be a little different.
Don't try to use a three jawed puller or pound on the flywheel to get it off, flywheels are expensive to replace!