Hold him your lap and give his ear a few gentle scritches, then treat and praise.
Once he is relaxed, then put dropper in all the way into ear gently, and drip it in. Afterwards, then rub the base of ear, for 10-15 seconds, to get it all the meds all of way in.
Treating and praising him everytime will convince him that it is a good deal. Because it is not painful. Hope this helps!