To trim a bird's nails safely, you will need a specialized tool called a nail trimmer designed for birds, which can often be found at pet stores. It's important to be very cautious and only trim the very tip of the nail to avoid cutting into the quick, which contains blood vessels and nerves. If you are unsure or uncomfortable with trimming your bird's nails yourself, it's best to seek the help of a professional veterinarian who specializes in avian care.