the easiest way to do anything with rooster or chickens that are not real tame, is to wait till after dark, if you grab him by the feet and hang him upside down he will calm down and it should be easier to get him up under your arm, butt to your front so you can check his foot easier. I give all meds that have to be administered to individual birds after dark, they don't run away or jump around so much, good luck
X2 that is what I do with my AB roos they are just like wild pheasants