Treats. Or give him a raw bone to chew on while you do it. You can have someone give i treats to keep him distracted while you administer the drops. A kicking dog is not fun when you're trying to help them.
I kinda treated "ear cleaning" like nail clipping. Make it a positive experience with lots of treats and a party afterwards.
Otomax on the finger and rub the ear and do it. If you pull your hand away in fear of being bitten every-time, when a true emergency occurs your in big trouble and the dog can't do it himself.. I allow Bella to play bite me all the time, she know's the boundaries. I am not afraid of my dog, it's other's peoples dogs you cannot judge them in 2 minutes time.