This can be a chore because cats clean themselves so anything you put on them they tend to lick off. It can be done though you will need to be diligent in your efforts. Start by using a flea shampoo and washing the cat then using a flea comb to remove the fleas as you do this dip the comb in a water/bleach combination to ensure they are dying. Then dry the cat best you can and apply a flea dip which you soak the cat with then allow to dry. After the cat is dry apply a insect repellent like frontline for cats to the back of the cats neck and watch he or she does not lick it off you may need a cone to prevent the cat from licking it until it dries. Then wash all bedding in hot water, apply flea powder to your carpets and vacuum it up as directed then be sure and toss the vacuum bag as soon as your done. Good Luck!