The most common treatment is vaseline, works best applied once a day. Yours have feathery feet, you could Adams Flea & Tick Mist, sprayed on and rubbed into the feet using rubber gloves. We have a Silkie roo though who gets scaly leg frequently, and we just use vaseline on his feather feet and it is basically ok. WE also soak the legs in slightly warm water with Epsom salts, once a day, or every other day, for about five minutes, you can soak longer though. Just make sure the water reaches all the way up the leg. You can add a few drops of flea shampoo to the water if you want. It takes seven to ten days of this treatment, sometimes more. You have to make sure all the scales are gone, you can gently scrub the legs in the warm water. You can also use any type of oil, Camphophenique, Triple antibiotic ointment. The idea is to smother or drown the mites, and then also bear in mind that there may be eggs which will hatch later, just like fleas, although all should be gone within ten days.
another treatment is to just use a Permethrin bath as a dip for the legs. I don't like that stuff as it's insecticide, but I've been told it works faster than the vaseline. If it is a bad case I crush a baby aspirin to mix in yogurt or something in their food morning and night, to help with pain and inflammation.
Important to start treatment immediately, as they can lose toes from scaly leg, or have permanent damage.