This was easy and I'm glad I didn't go to the trouble and expense of hiring an appliance repair person. I'm reasonably handy, but I really have no experience in this kind of repair. I'd like to mention that the part I ordered arrived in just two days and it was exactly the right part, so I was very pleased in that regard.
After turning off the circuit to the wall oven and confirming that the power was off, I had to remove the oven from the wall in order to access the wires and connections in the back. Normally, this wouldn't have been necessary because usually the broiler element can be disconnected from the clasps that connect it to the electric source by simply unscrewing the defective element from the roof of the oven, pulling gently on the connection ends from inside the oven cavity in order to "pull out" an inch or two of the electric source wires and the metal clasps that accept the "male" connecting ends of the broiler element. Once the a bit of the wire and the metal connecting clasps are exposed and able to be held with pliers, the element can be disconnected from the connector clasps by simply pulling on the prongs of the element (hard).
But in my case, one of the metal connecting clasp for one of the wires had melted, presumably when the element burned out, and that clasp could only be accessed and replaced from the back of the oven. Also, I would imagine that the wires and clasps could "slip" back behind the unit when they're disconnected if that's not done carefully. However, removing the wall oven was pretty easy for me -- even as a one-person job. I just put a tall table in front of it and slid it out so that it rested on the table.
If you have to replace a metal connector clasp, they're inexpensive and available in the electrical departments of hardware/home stores.
In my case, there's a metal panel at the back of the oven that had to be unscrewed and removed so that I could access the areas where the electrical source wires connect through the back wall of the oven to the broiler element. This was just a matter of removing a few screws and then removing the metal panel.
Once the metal panel at the back of the oven was removed, I was able to replace the melted connection clasp by using a wire cutter/stripper and then pliers to secure the clasp on the end of the exposed wired by deforming the clamp with the pliers. Once that was done, I simply removed the screws that held the broiler element to the top of the oven cavity, disconnected the remaining three clasps that connect the element to the source wires (the fourth clasp was the one that had melted and that I'd replaced), removed the defective element, inserted the four "male" prongs of the broiler into the four clasps that connect them to the source wires, replaced the metal panel at the back of the oven, screwed the new element back into the top of the oven, slid the oven back into the wall cavity, turned the circuit back on, crossed my fingers, and everything worked like a charm.
I saved a money, but more importantly (for me) I saved a lot of time that I would have had to have spent waiting around for a repair person.