when removing i use air tools. you could also use a HD cordless impact.
when torquing down i have found changing the angle of the wrench also helps. instead of torquing down from the outside, the handle is actually outside the circumference of the flywheel. say the bolt is at the 12ocklock position and you hold the wrench at the 3 ocklock. torque from the center across the flywheel. say the bolt you are torquing is at the 12oclock position, hold the wrench at the 9 or 10 ocklock position.
you could also use a screwdriver in the teeth of the flywheel and the shaft is on the edge of the block to keep it from turning.
or you could use a tool designed for the job, flywheel holder/ turner like this
http://www.ebay.com/itm/Flywheel-Tu...848311&hash=item2126196805:g:3toAAOSwhvFZDFiV