Delete a keyframe
You can delete a keyframe if you want to delete the property change that occurs at a specific point in the timeline. The property will then animate smoothly from the previous value of the property to the property's next known value. Optionally, you can copy or move the keyframe using the procedure that is described in Paste or move a keyframe.
Deleting a compound or object-level keyframe will also delete all the child element keyframes.
Select the timeline from the Storyboard picker by clicking Open a Storyboard under Objects and Timeline and then selecting the storyboard that contains the keyframe that you want to delete.
Use one of the following methods:
Click the keyframe that you want to delete, and then press DELETE.
Right-click the keyframe that you want to delete, and then click Delete.