To get to the plugs, remove both side fairings, then unbolt the radiator and let it hang down leaving the hoses connected. You will be able to reach the coils and plugs from the front. It's still tight, but you can still wiggle things around to find room to get the coils out and then get the plugs out with the proper combination of socket extensions. I recommend disconnecting/removing one coil and plug at a time, then reinstalling it before doing the next one. That way you can't get the coil connectors accidentally connected to the wrong plug.
As for winterizing, I don't add oil to the cylinders. I change the oil and filter, lube the chain and cables, then cruise to the nearest gas station with a bottle of Stabil in my pocket. Add 2 oz. of Stabil to the gas tank (1 oz treats 2.5 gallons), fill up with gas, ride around for 5 or 10 minutes to make sure the Stabil is mixed, ride home and park it, then connect my cheapo Harbor Freight Tools float charger to the battery. I also park the bike on stands and drop the tire pressure down to about 20 psi. If you don't have stands, park the bike on some plywood. Lowering tire pressure and getting the tires off the concrete helps keep the tires from drying out or dry rotting.
Since we sometimes get an occasional unseasonably warm day here, I may ride some during winter, then just add more Stabil while topping off the tank before heading home. Anyway the weather goes, I at least start the bike and let it run for 10 minutes or so every week or two.
My F4i has almost 29000 miles on it and this is how I've winterized it since I bought it new in 2005. No leaks, no smoke, no noises, no problems, valve lash is always in spec when checked, etc, etc, etc.
