locking down the fly wheel

do i need to get the tool to lock the fly wheel in place when breaking that crank bolt loose?

You can get one that bolts in place of the starter and engages the flexplate teeth.

I just put the impact on the crank bolt and hit it until it came off. I didnt lock the flywheel until I put the crank pulley back on. I used a screwdriver.

the screw driver worked out good for you?

That is correct. It will come off without locking it but to put it back on it must be locked. The steps involved in reinstallation put the final torque value near 275 ft/lbs (it has angle measurements but my electronic wrench gives the final total).

If not impact, just cram a pry bar inbetween the crank pulley and the block--not against the powersteering pump or anything else aluminum. Spray some WD-40 on the bolt about an hour before. Then get a decent size 1/2 ratchet on there and use your floor jack handle as an extension to get more leverage out of it.