If the band's are working they are very tentative about using them or even getting bumped in the head, there will be no using them, normally a goat will use his horns a lot, especially when playing or fighting over food, bashing their herd mates.
If you can catch the one without bumping his horns and hold him really still and kinda wiggle a horn he would let you know pretty quickly that it hurts by screaming, the one with the single horn will probably lose it eventually, it can take a couple of months for band's to work and sometimes they hang on by a little bit, never pull them off, it hurts and can bleed profusely.
If the horns appear firmly in place to where there no give and the goat doesn't scream you are probably safe to remove the band's, a quick snip with a scissor will do it, though unfortunately you will have one with horns and one without, some with horns can be bullies.