It shouldn't be a big deal, as the stimulants enter and leave your system every day anyway. The half-life of Ritalin is about 3.5 hours, so it never reaches a steady state plasma concentration in your body; it's constantly going up or down.

In my experience there really isn't any withdrawal to speak of, but you will feel more tired than you're used to. This could last a long time or just never go away, as the stimulant aspect often counteracts the sedation present with some of the other meds you're on. Good luck, I hope it works out well for you.