I replaced the convection fan assembly. It is removed from inside the oven and consists of the fan and a heating element. Disassembly was easy, just remove the oven door, a sheet metal cover, then the fan assembly, unplug the fan's one wy plug and the two leads to the heating element. The only issue on reassembly was plugging the leads back onto the heating element. The leads are a little too short to assemble from inside the oven. I was able to do it by having a second person help. Those leads are obviously designed to be attached after the fan assembly is screwed into place, but that would require pulling the stove out of the cabinet and accessing from the rear rather than from inside the oven.
Remember to shut off the power before this job