I would like to take advantage of the latest double avios offer, but have a number of bookings in Y and J. I would like to remove the Y sectors to try to maximise the 8 sectors in J only.

I would appreciate any advice from the FT community on the easiest way to ensure that all traces of my Exec Club number are removed from a booking.
Also, if I do this, will my current selected seating disappear from the bookings where the Exec Club number is removed ?

Any guidance would be much appreciated ...