Method 1:  Take a spray bottle and fill it with soapy water. Splash the leaves of infected plants with this and rub off. This will not only clean the plant but prepare it for further treatment.  Now dab a cotton with 70% Isopropyl alcohol and rub the leaves with especially underneath to wash away all the infestation.   Remove away all the mealybugs by hands. If needed gloves can be used else they do not bite usually.  The above process needs to be repeated weekly to eradicate the infection completely since mealybugs are good at hiding between crevices. They need to be treated regularly.  Method 2:  In another method, one can use Neem oil for potted and shaded plants. Mix together water, dishwashing soap and neem oil in a spray bottle in a ratio of one teaspoon of neem oil and 2-3 drops of dish wash soap.  Now do not allow the direct sunlight after this treatment else keep the plant in shade. If treating the open plant then wait for the shady day with lower temperature.  The repeated application of this spray needs to be done to completely eradicate the problem or the bugs will appear again as they have a rapid lifecycle.