Bad Lead Reasons can be managed in your company settings by navigating to settings-> Sales -> Bad Lead Reasons

Several actions can be performed on the bad lead list.

Add Row: Clicking add row will show a slide-out that will allow you to add an item to the list.

Edit: Clicking the three dots menu at the end of a row will allow you to edit the name of an existing item

Delete: Clicking the three dots menu at the end of a row will also allow you to delete the entry entirely.

Re-Order Items: By clicking and holding the pointer on the reorder icon (just to the left of each entry) you can drag each item and re-order the list.