If it's a newer bike and something is rubbing, they can be a pain to try to break off. But doable -- just requires a bit more tenacity and work.
If the reason it is making noise is because the tabs holding it to the spokes have broken off, chances are it is brittle enough to easily break off in chunks with pliers.
As others have said, make sure the low limit screw is set correctly. Test is to shift to lowest gear/biggest cog out back and sight the chain vertically in the same line with the biggest cog. If the top pulley of the derailleur comes to rest more inboard than the inside cog, make adjustments. Otherwise, catastrophic failure can result in the derailleur in the spokes, broken spokes, bent chain, broken derailleur hanger, and in severe cases, broken frame.