This is certainly a inadequate design. There are postings all over the internet referencing this problem. Here is what you have to do to replace a broken handle:

First, understand that the door design is optimized for assembly, not diassembly. The design engineer that was responsible for this POS may have thought about the poor schmo that had to try and fix this thing, but not longer than it took him to run to his boss and tell him he just saved 13 seconds of some chinese assembly persons time on every oven. So take a deep breath and go to your patient place.

Second, if you have not already ordered the replacement handle, you might want to go ahead and order the black interior fascia plate. Chances are about 90% that you are going to break off the little arms that hold this sucker in place when you remove it.

The first step is to remove the oven door from the oven so you can work on it. You do that by moving the door up on it's hinges and prying up the hinge plates on the door with a screwdriver so they clear the gudgeon on the oven itself

Once you have the door off, lay it on a table with a blanket or cloth to act as a buffer so you don't scratch the door (or the table). Next you have to CAREFULLY pry back the edges of the door in order to release th plastic fascia. Work slowly and carefully. You will still probably break those fingers I mentioned before, but you hopefully won't crack the plastic trim piece itself.

Once you have the black trim piece removed, you will be able to access the top screw holding the handle to the door. Unfortunately, you will not be able to access the bottom screw. More work to be done. Remember what I said about optimized for assembly and being patient?

To get to the bottom screw, you have to remove the outer plastic fascia from the interior core of the door. To do this, first remove the six screws fastening the door to the exterior plastic trim. Then CAREFULLY pry back the edges of the plastic trim to release the core from the trim. If you work slowly and carefully, you probably will not break anything here.

Once the exterior trim is free of the core, you will have access to the upper and lower screws that are used to attach the handle. If you are lucky, the handle has broken off is such a way that you can hold the plastic stub that is left with a pair of pliers while you back out the screw. But likely, the stub have broken off flush so you have nothing to grab onto. In this case the assembly will just spin with no easy way to stop it so you can back out the screw. I finally had to drill a couple of very small holes in the stubs and insert some small nails that I could hold fast with a pair of pliers.

Now all you have to do is reinstall the handle and put it back together. Getting the little screws that hold the exterior trim piece to the inner door core is a bit of a pain because you can't get your fingers in their to start them. I used a pair of needle nose pliers to get them started.

Good Luck!

The Advantium is at our house in PA not here in NJ. What is the part number of the handle so I can order two (Guess from what I read we'll need to keep a spare on hand. Lousy design...
Any help appreciated, so I don't have to travel up just to get the model number.
Thanks,
Van
Fair Lawn, NJ

what i did was i went to lowes and bought a product called loctite- its a plastic bonder that contains an activator that you use before you apply super glue
its been four months and we have opened and closed the door about 800 times without any problems
if you have kids that are going to be unusually rough when opening then this method may not work
in my house we open it it in a normal manner - we do not baby it or even think about trying to be gentile with it
i hope this helps
also if you decide to repace the handle- get them to send you a handle free of charge because this was poorly made