Some different treatments for Melanoma are surgery, radiation, or chemotherapy.
Surgery: The tumor or cancerous cells are cut from the skin, and so is some of the surrounding tissue. This treatment is known to be the most successful.
Radiation: High energy X-Rays are used to kill the cancer cells and to prevent their growth through the use of an outside machine, known as external radiation, or through radioactive needles and wires called internal radiation.
Chemotherapy: Drugs are used to stop the growth of cancer cells by killing them or halting their dividing. The drugs can be taken in the form of a pill or injection, or applied as a cream. However, the lotion/cream form can possibly cause inflammation and scarring. This type of treatment is used to treat skin cancer that has spread.
Bill's best option would be surgery since his cancer is still small and in one area. Radiation or chemotherapy would be a poor choice since they are commonly used for widespread cancer, carry more harmful effects, and aren't as successful as a surgical removal of the tumor.