Eraley

New to this site so please be patient. New to me 2012 glk350. Previous owner lazy and replace headlight bulbs by breaking clips then just setting light loosely so part of the section where bulb sits is melted. I am pretty sure I need to replace the whole assambly how do I do that? Does bumper need off and if yes is there a how to? Pictures, video anything will help. I have thought bout just trying to replace clip and bulb but not sure if I can. I have pictures really need help before I have to spend 1,000 to replace bulbs. Thanks