Bumper? Naw he's talking about the door panel retaining clips. I'm sure he's talking about the white colored clips found on the back of the door panels to hold them to the door. Here is the honda part number: 91560-S84-A01 and it's called a door lining clip and the color is "natural". They are $1.13 if you order it from bernardiparts.com or $1.50 from a honda dealership. Most of them have these in stock b/c they are the same for most honda's.
They look sort of like this (this is not a honda clip. i just found it on google but it's the same design/color)
They do have a tool that can help u remove these clips without breaking them. It looks like this and can be bought at any auto parts store. it's called a Panel remover tool:

or
But honestly, when i pull my panels off, i just start from the bottom and do quick jerks at the panel to pull them off and i only have one of the 10 clips stay in the door, the rest stay on the panel. That's the best way to reduce having them stuck in the sheet metal and having to use pliers 2 remove them.