How can I change my flight information (or rename my trip)?

This is easy to do. If you need to edit the details / delete a flight included in a trip, you need to split it and then edit each flight. For more information, see here: How to Split Trips.

iOS

Edit trip name

Swipe to the left on the trip and tap Edit.

Rename it.

Edit flight details

Swipe to the left on the flight and tap the blue button.

Then you can edit the flight information (as well as its name).

Android

Edit trip name

Press and hold the trip, then select the Edit button.

Rename it.

Edit flight details

Press and hold the flight, then select the Edit button.

Then you can edit the flight information (as well as its name).