Have you always had them? You will need to consult a doctor on the best measures to get them removed, depending on the cause (for example, are they more birth marks or something that has appeared over time due to sun exposure, ect)
The more recent ones I would have looked at by a doctor to make sure they are not appearing as a result of another skin condition- but in both cases the doctor can help guide you through how to take steps to get them removed.