Can you post a video? I get really confused for the steps:
5. Place the rotation lock switch in the up position (so you see the red markings)
8. Once the tablet vibrates, switch the rotation lock on and off repeatedly while still holding the Volume down button.
9. Release the Volume down button and stop switching the rotation lock once the "Erasing Userdata..." message appears in the upper left corner of the screen
I don't know how to perform these steps exactly.