You might have to loosen or possibly remove the front cladding to get the covers on. Another option is to apply some silicone LUBRICANT to the cover tab that goes below the headlight and shimmy (read FORCE) the lower cover tab inward. If it's a real tight fit, the cover may actually scratch or gouge the softer cladding plastic. Once the lower tab is fully inserted, all that's left is to clip the cover over the top of the headlight housing and/or re-tighten/ reinstall front cladding.