Main toolbar > Open Track View > Select keys in the Track View Edit window. > Track View toolbar > Delete Keys
Graph Editors menu > Track View > Open Track View > Select keys in the Track View Edit window. > Track View toolbar > Delete Keys
To delete keys in Track View, you first select keys and then click Delete Keys.
To delete all keys associated with an object, select the object name label in the Hierarchy list and click Delete Key, or the DEL key. If you delete all the keys in a track, the value for the parameter associated with the track is set to the value at the current time. This applies to Edit Keys, Edit Time, and Function Curves mode.
Procedures
To delete selected keys:
Select one or more keys.
Click Delete Keys.
To delete all keys for a selected object in Track View:
In the Track View Hierarchy, click the object name label.
Click Delete Keys.
A Delete Keys dialog displays, warning that you are about to delete all animation keys for the object.
Click OK in the dialog.
Interface
Delete Keys: Deletes selected keys in Track View. May also be accessed by pressing the DEL key, but make sure that the Track View window is active (otherwise, the selected geometry in the scene will be deleted).