Remove driver and passenger side under dash covers
Remove driver and passenger forward console side covers
Remove glove compartment
Remove body control module and supporting brackets
Remove passenger side fan blower cover.
Inspect inside of blower fan if possible. Noise might be just a piece of debris inside the blower fan. Debris can fall through from the outside intake vent.
Remove accelerator pedal
Disconnect blower motor plug on drivers side of blower.
Have helper twist the fan assembly on the passenger side while holding down a hard plastic locking tab on the driver side. Tab must be depressed or fan will not turn. If depressed, the fan turns pretty easily.
Make sure accelerator pedal, all plugs and all electronic modules are in and reconnected before attempting to turn on the fan or otherwise start the car.
When I did this I followed the directions in the Chilton’s online service manual for a 2015 MKC. You cant purchase it but it is available through public library access.
In the manual you have to look at blower motor removal instructions then inside those you have to go to other instructions like control module removal instructions and fan cover removal and accelerator pedal removal instructions and so on. It is clear when you read them but it isn’t just one set of directions. There are photos and diagrams which make it easier to follow. There is a difficult screw to get out in a support bracket above the control module. You will know it when you see it. The top of the screw faces away from you. I finally got it off and reinstalled using a short 8mm ratcheting closed end wrench. There is also a deep hidden screw on the upper firewall side of the fan cover. The only way I could see it was with an endoscope. You can probably feel it and remove it with a flexible extension driver, but unless you have a scope it might be really hard to see where to get it back in. Maybe you could use some silicone sealant, tape or other material to kind of hold it in place when you put the cover back on. Twisting the blower fan loose requires holding down a stiff plastic tab on one side of the blower and twisting on the other side. If the tab is fully depressed the blower will twist out, but if the tab isn’t clear the blower will not turn. The instructions say it takes two people to do that and I totally agree. All in all it took me about 3 days to get the old fan out and the new fan installed without breaking something. Most of that time was spent sorting out the problem spots I mentioned above. If I have to do it again it will take less than an hour. Patience and don’t force things are keys to success.