Airlines allow minor spelling corrections on a name — typically a few characters — usually for a fee, and only before departure. Replacing one traveller with another is not a correction and is not permitted on most fares.
Tell us as early as you can. Raise a request from the booking with the exact spelling as it appears on the passport, and we will take it to the airline and come back with the fee, if any.
Names must match the travel document exactly, including the order of given names.