A month? That is highly unrealistic if not impossible. Try 3 months if you work your ass off.
Any arm exercise workouts will help. Tricep dips bicep curls etc are great. If you have no weights use soup cans or pop bottles.
Whatever you do learn to make realistic and achievable goals or you will find things very tough. You didn't get flabby arms in a month And your almost certainly not gonna lose them in a month
Alan R. is right don't expect miracles to happen, but you already know that. Tricep dips work great, push ups too. Mix it up. I put 3 different kinds of push ups in my workout (20x10). Its fun and challenging. Also pull ups will chisel your biceps, triceps and upper back. Let me know if you need anymore ideas for arms exercises. Good luck and God Bless!