I need to remove my rear derailleur so that I can attach an alignment tool and straighten things out.
Images of the rear derailleur while the bike is upside-down:
Where is the derailleur's hanger's bolt that attaches the derailleur to the frame?
- Find a hex wrench with a long handle (at least as long as the 3-way hex wrench from Park Tools)
- Turn counter-clockwise in the area circled in red by Jerry.