To edit the content of objects in animation frames, use the Layers palette to modify the layers in the image that affect that frame.
To change the position of an object in an animation frame, select the layer containing the object in the Layers palette and drag it to a new position.
To reverse the order of animation frames, choose Reverse Frames from the Animation palette menu.
To delete selected frames, select Delete Frame from
the Animation palette menu or click the Delete icon , then
click Yes to confirm the deletion. You can also drag the selected
frame onto the Delete icon.