Well that's me grounded

On my futaba tx's - the screws holding the sticks in are on the front of the case, four to each. The circuit board on the back of the stick doesn't need to be touched.
The snag is - the sticks have to be rotated 90 degrees for the trimmers to line up with the holes in the case, so you end up with the throttle working left/right. the rudder working up/down, etc!
All that needs to be done, really, is to take the little flat ratchet spring off the throttle stick, and the coil spring off the ele stick, put the ratchet spring on the (old) ele stick, and the coil spring on the (old) throttle stick. job done! (Then remember the sockets on the rx are marked wrong!)
Getting the little coil spring onto the plastic hooky things that centre the stick is a right pain, though! Tie a length of cotton to the spring BEFORE you touch it, or you will spend a month looking for it when it flirts off!

This works on a simple tx, but if you are computerised, with about thirty different mixer options, then the fun starts!

Nail on head as usual Eric.

Dead easy once you pluck up the courage, wasn't it?