The starter goes thru that hole in the cover. Cover won't come down without removing the starter. Definitely take the plugs out when turning the motor over. I believe the motor turns clockwise. If I recall correctly the end of the crankshaft is threaded, but the factory didn't put a bolt in it. They plugged the bolt hole with cork. I believe you can take the cork out and install a bolt in the end of the crank. I don't know the exact size, but I recall it being 9/16", not sure of the threads per inch.
Can you grab the lower pulley (two hands with gloves) and spin it around?