We then began cutting the arm off. In his video, Conrad recommended using Dremel's 420 and/or 540 cutting wheels. The 540s are bigger and would need to be ground down to fit the tight space but can cut through much easier. Of course we only found cutting wheels labeled "heavy duty" at our local hardware store. These wheels were very thin and brittle and we burned/broke through more than a dozen of them. We would definitely advise following Conrad's recommendations.