The SOP for exchanging "old" bank notes with "new" ones is very similar throughout Europe, but deadlines do change. I've been through a few such changes (last one being Drachmas, Lire and DM to €) and more than 20 years later I still find some relics from the different countries I've lived in at several, unexpected places in my house. Anyway, after a period lasting several months to a couple of years after the change when both kinds of notes are legal, you can exchange old for new at all local banks for a few more years (~5±). From then one an exchange is only possible at branches of the different central banks of the individual country for a rather long period (I'd say decades). Whether such a procedure can be carried out fast or not is a big question and I doubt that you'll get a good answer in a forum such as this. The big difficulty will always be finding a branch of the central bank of which, usually, there are few, given that the work they do is not addressed at "common people".

Anyway, here is official info on this matter, provided by the SNB!