First thing throw out all the bedding the snake has been in contact with. Put the snake on newspaper or paper towel or the like. Get some mite killer ASAP. I use Reptile Relief and it works great and it's safe. Pam is good too just crazy expensive. Next if the snakes cage is near a carpet vaccum it really good everyday for till the mites are gone for 5 days. Mites can lay eggs in carpet and after they hatch they can reinfest the snake and you have to start all over again.

You can read some more about mites if you'd like here.
http://www.vpi.com/publications/the_...of_snake_mites