Originally Posted by
vip66
However, I also read somewhere that airlines may decide to charge you for not using the return leg, although this is very rare.
Has anyone had any experience doing this?
You can just cancel the return leg of the old reservation (you can even do it online, I think). There is no change fee/penalty unless/until you decide to use that return leg as the basis for a new booking. If you do nothing with it, it'll disappear after a year.