I've actually done this before, but unfortunately so many years ago I can't clearly recall how. I seem to recall it involves some unusual bolts around the column which hold on the switch assembly (and the steering wheel lock mechanism). They are unusual in that their heads are broken off during assembly - leaving only smooth round heads and a little broken shaft. Cut a slot in them with a Dremel or similar then use a heavy screwdriver to get them out. Easier than swapping the entire steering column, anyway.