How to multi select the parts for rotation

Step 1. Toggle the “Multi-Select” button while in the animation editor form the menu bar at the bottom right corner of the canvas

Step 2. Select the components you want to rotate by left clicking them

Step 3. Enter the rotation value in any of the 3 fields in the “Multi Select Rotation” section of the side menu

Step 4. Select the desired direction by left clicking on the “CW” (Clockwise) in the X, Y, or Z axis field. This will toggle it to “CCW” (Counterclockwise). Left click again to switch back to “CW”

Step 5. Left Click “Apply Rotations”

Step 6. Left Click either “Next Frame” or “Save