Use a T15 to remove glove box. Some signs of why lever is not working. It gets worse
8mm to get 3 screws off of front of heater core and 2 more in the back. Remove cover. Already signs of a mouse making a home in here at one time. No idea how pencil was in there.
Remove hoses under the hood and work core thru carefully and not spill fluid inside.
I removed my Air Filter Bix and the 3 screws to get blower motor out. More debris. This is why my lever is not moving. Seen it on the Ranger. Will order a new Heater Core.