You are supposed to drop one feed per week and replace it with formula. However, with at 2 month old baby, that could see you taking six weeks or more to stop. Going that slowly will avoid breast pain and mastitis, but it might not be satisfactory if you are desperate to give up! Perhaps try replacing one feed every four days? At that rate you should be totally done in less than a month. The last feed to go should be the bedtime feed ideally but that is up to you. If you have pain in your breasts, express a tiny bit, just enough to relieve the engorgement but not enough to stimulate more milk production.