What steps should be taken to fix a bent rear derailleur hanger on a bicycle?

To fix a bent rear derailleur hanger on a bicycle, follow these steps:

1. Remove the rear wheel.
2. Use a derailleur hanger alignment tool to straighten the hanger.
3. Check the alignment by eye and with the tool.
4. Reinstall the rear wheel and adjust the derailleur if necessary.

It is important to be gentle and patient when straightening the hanger to avoid causing further damage.