Pentuner said pretty much what I was going to say about this guy...I'd have run him off when he showed up.
That said, you'll need to see if you can find a horseshoer to look at your goats' feet. Yes, they are bad right now and will give you problems if you don't get them trimmed. Goats have a poor constitution for pain and if they start to hurt them too much, they will start laying down a lot and this can really accelerate arthritis in the goats' knees. I have seen one goat that was so bad, its knees were frozen at almost a 90 degree angle because of the amount of time it spent laying down...this was an extreme case where the goat had foundered, but you get the drift of how bad it can get. You don't want to let that happen.
Tools-wise, you may be able to get away with goat hoof shears or you may have to get regular horse hoof nippers and a farrier's file. For these Nubians, I'd go whole hog and get the horse tools, but the goat snips are good for the fine tuning. But be sure you have a knowledgable farrier or goat person show you how before you attempt it, because you don't want the goats' feet to bleed or get sore from the trim. It's too hard and error prone to try and tell you in email how to do it without physically being there to show. These are big goats, so don't be afraid to lay them on their sides to do them...just be cautious about how you keep them there. Putting a knee into the goat's neck to hold them there is NOT a good idea, the blood supply to the brain can be easily choked off and kill the goat. You would be much better off to just have a second set of hands to help, or tie the goat to a post and do him with one leg up like a horse. Good luck!