In the engine bay, the blower motor just has 3 maybe 4 screws that hold it to the Air Box
Pull it off
There is a rubber hose on the motor part, pull it off, its the vent for the motor, so if engine bay has an oil or gas smell it can't come into the cab via the motor
This is a NON-AC air box, you can see how blower/fan comes off and also can see Resistor Block:
https://www.explorerforum.com/forums/attachments/0900c1528018eee1-gif.372490/
AC Box seen here:
https://www.therangerstation.com/Magazine/Summer2009/heater-core/heatercore4.jpg
Reach in and you will feel the Fresh Air vent going UP, fresh air comes in from far passenger side under the cowl, not visible from outside, clean it out
Reach in toward drivers side and you will feel the Evaporator(if you have AC)
remove and vacuum out any debris
There is a Vent flap direct inside that's behind the glove box, thats the recirculation vent door, it can close off the outside air vent so fan only pulls in air from the cab, so it recirculates cab air, used for MAX AC
To the drivers side is also the Resistor Block, has 3 resistors/coils and a heat sink, its for the blower motor, it gets very hot which is/was the burning smell if leaves were touching it
Looks similar to this:
https://easyautodiagnostics.com/images/articles-700-799/790/795/image_1.jpg
Its located in the air box to cool it