First remove the internal fan guard, (two Philips Screws). Holding the fan blade and using a nut driver (10mm?) attempt to carefully remove the nut off of the shaft. If it loosens with a counterclockwise rotation, it is a Right Hand thread, Part#: PS11720788. If it loosens clockwise, it is Left Handed and is Part# PS11720787. When the correct fan arrives, check to make sure it matches, then continue with installation.
TURN THE POWER OFF
Following the door removal instructions in the Owners Manual, remove both upper and lower doors. Remove the screws that go into the cabinet on the sides, I believe there are (6). The bottom vent cover is also attached with the bottom screws, so you can remove that and set it aside.
Get some help to assist you with moving the stove out of the wall cavity, it's not heavy, but awkward. I used a small furniture cart, and the second time I used blocking on the cart to raise it to just below the oven and was able to easily slide out/in.
Rotate the oven so you can visualize the back. There are two panels on the back to remove, Starting with the bottom one, remove the screws, (a couple in the middle too) and slide the panel up, (Tabs into a notch on the top of each side of the panel) The second panel comes off the same way, there may be some screws on the side and top you need to be aware of. Once you open the back, the fan that needs to be replaced should be identical. If you have already removed the guard and fan blade from the inside compartment, it should be a simple swap out.
Put it back together in reverse order, put power back on and check to see if it worked. If so, slide it back into the cabinet, be careful the flex conduit is aligned so it doesn't interfere. Second time around it only took me about an hour total and I didn't need assistance.
Fan works, Oven quiet, Happy Wife, Happy Life.