The repair was very easy, however the bulb was not the same as the original one. The original bulb had a bright setting and a low setting, but the replacement bulb was only the low setting bulb. There was no bright and dim operation. The switch on the microwave had the duel settings.
Removed control panel, discharged HV capacitor. Removed old diode, tested to confirm failure. Replaced part. Other than the removal of the panel swapping the part was almost as easy as replacing a light bulb.
First I read through the customer comments, reviews, questions, etc. at Parts Select, which is always a good bet. Then I put "samsung microwave door switch replacement" into youtube and watched some videos. They don't even have to be for Samsung. From what I can tell, many of the appliance companies use the same design and the same junk parts, so watching a GE video is almost the same for example. Watch some videos to familiarize yourself with the steps. There are maybe six to disassemble and install the new part. I replaced all three switches. They are not expensive and to replace 3 is only 5% more work than to replace just one; you have to take the microwave apart in either case. UNPLUG THE MICROWAVE FROM THE WALL. Start taking it apart. I use my phone to take a picture of any thing I remove, unscrew or disconnect, especially wires, BEFORE I disconnect them. Thee pictures serve as a reference when I go to reconnect and reassemble. If I am uncertain then I check the picture. Good luck!