I have always come in from the top. I pull the battery, then rotate the tank up on a pad in the battery recess.
pull the air filter top, airfilter, coil mounting screws and the venturies. There are a couple of sensors that unplug. You can now remove the bottom of the breather box.
put clean towels or paper into the intakes now.
I can't sink a basketball anymore, but drop a screw, and down the intake it will go.
I then do one plug at a time. Use the plug wrench that comes in the tool kit. It works well.