1. Carefully with mild soap and water, preferably just dabbing to avoid removing the makeup as much as possible.
2. For the head and face, I just use a damp cloth with no soap at all and spot clean with baby oil and a Q-tip as the need arises. I usually follow that up with a very, very light dusting with cornstarch.
3. I use regular strength blue Dawn dish soap to give my WM a sponge bath. About a teaspoon in a couple of quarts of warm water. Been doing it that way for over 3 years now without incident.