There are two possible routes to take. One is to call professionals to deal with the infestation. This is recommended if there are a lot of fleas in your house. If the infestation is small, you could try to treat it yourself first, but you have to act fast.
Purchase bug sprays and inspect the house. Try to find out where the fleas are. They might just be in one room, but they might be in several rooms.
Take any pets, other real animals, family members and food away from the room you will be using the bug spray. Leave the stuffed animals in there. Follow the instructions on the spray and use it.
After enough time has passed in accordance with the instructions, return to the room and inspect it. Take a vacuum cleaner and vacuum the entire room thoroughly, including the stuffed animals. Then immediately remove the vacuum cleaner bag, put it in another plastic bag, tie it up and throw it away.
Next gather the stuffed animals and put them in a plastic bag. add some boric acid and shake the bag with the toys in it. Leave it for a couple of hours.
The next step is to wash the stuffies in the washing machine or do a surface wash if that is what their label recommends. Leave them to air dry and they should be well cleaned and flea-free.