Opps! Bulb in tail light

Hello,

I was in the process of changing the regular bulbs into LED lights for reverse light. It's a tight squeeze to get you hand into the back of the tailight. Well, when putting the new LED it fell into the tail light housing. Anyone have any suggestions? I believe I might have to remove the rear bumper. But I cant find any instructions on how to do it. I dont want to make this worse. ( I should have just left it alone).