Remove entire cowling assy. 1 or 2 bolts in cylinder head, and 2 on crankcase. You may need to disconnect the speed control if it's attached to the cowling (depends on model)
If the coil is mounted outside the flywheel, unbolt and disconnect it, and replace.
If the coil is mounted under the flywheel, you will have to remove it (respond on this thread if you need to know how). Unbolt magneto assy, and dissasemble to extract coil.
phil_saunders@bigfoot.com
Phil Saunders, January 2009