How to edit a workout?

A recent workout claimed I burnt 2400 calories. Turned out a Bike ride was logged as an Outdoor Walk.

How can I change the workout type and have the calories re-calculated?

If not, how can I manually edit the calories themselves?

Thank you.

BTW, I would think the app would be smart enough to deduce that I was unlikely to be sustaining a walking speed of 12.4 mph over 22.6 miles and ask me if I wanted to change the activity.