My return flights TRN to CDG via NBO have both been cancelled. These are revenue tickets in J (Z bucket) booked direct but it’s not until the autumn so I’m in no hurry to sort them; except that my positioning flight is now useless (AF to LHR).

They are offering a free change one day later which we can live with but what I’d like to do is change the return to LGW (it was booked before they launched). Is that possible, as above?

if it is, what chance do I have to get the outbound from LGW too?