Detox from Snorting Ritalin

My mother is 59 and called me tonight to tell me she has been snorting her ritalin for the past 13 months. 20 years ago she quick cocaine. 15 years ago she quick alcohol. She has obsessive compulsive disorder with germs and lists and is on Prozac, Ritalin. She is also prescribed Vicadon daily for her migraines. Other medicine to that I don't know the name of for brain siezures? Because of all this medicine she can hold a job. She wants to quit snorting Ritalin but not tell her doctor because she thinks he will take her off some meds that she feels she needs to survive. She can't afford the price of meds if they are given out in two week increments. Can she quick cold turkey on the ritalin. She got the doctor to up it to 6 10mg pills a day. She knows she does not need this much. She doesnt want to tell my Dad. Wants to quick on her own. She has quick things on her own in the past. What is a safe way to get her off Ritalin? Help please. She said she is starting to feel ill and thinks this will eventually kill her if she does not stop.