Originally Posted by eternaltransit

OP: you can easily do this, people do it all the time - if the outbound has been flown EK can do it for you at a ticket office, or you can call your TA. You'll have to pay a change fee (ex-LGW it's probably 75 GBP) as well as the fare difference to the next available Flex Plus bucket. You would have to upgrade both sectors as EK generally won't split the inbound into two separate flights.