With a dog like this, I'd probably just muzzle it and get it over with. If I am unable to muzzle a dog to medicate it's ears and so on, I try things like really high value delicious treats to make the ear handling less stressful. If the dog has a mouthful of delicious treats and I can sneak the medication in the ears, then I can back off before it's got time to snap.
I think it helps that I've had a LOT of years of working with a LOT of different animals, and can be super sneaky and fast with some of that stuff.
My Dog: Krissie ~ Beagle Mix Extraordinaire 09/09