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This range hood/microwave/convection unit installed January 2002.
First broken handle replaced by a Sears tech July 2010.
Second broken handle replace by me May 2014.
This handle isn’t impossible to replace, but it’s not easy. I watched the first replacement, and the Sears guy struggled with it, plus he broke off some plastic retainer tabs. There’s a video link on this site that’s supposed to show how to do the handle replacement, but it only shows you how to get the door off the unit. I’ll see if I can do better.
Let’s begin. Have a double-dose of patience at the ready. :eek:
UNPLUG the microwave from the wall socket. (You don’t want to be lighting-up while replacing the door handle). 
Take out the two phillips-head screws on the top of the grill vent above the door opening, and remove the grill. Set aside for later.
Being very careful while the door is held open, lift the door at the hinges, and gently pull the door away from the hinges.
Set the door, handle side down, on something soft (like a towel) that’s been spread out on a counter top. For purposes of my explanation below, orient the door with the handle on your left, setting on the soft counter surface.
Gently pry around the outside of the flat dull-finish plastic frame with a small flat-blade screwdriver between the (gloss-finish) outside door frame and the 2" plastic frame, and lift the plastic frame away from the outer frame. It’s held to the outer frame with plastic tabs positioned behind the frame, around the perimeter of the frame. Set it aside.
Now you can see the handle’s upper screw. Don’t get excited. That’s just a teaser. You’ve got a lot more work to do to be able to access the lower handle screw.
What you’ll see in front of you is a metal frame that looks like it has metal tabs/teeth surrounding the inside glass panel. If you look very carefully, you’ll see six small phillips-head screws, three along the top long side, and three along the bottom long side. Carefully remove these six screws, and set them aside.
Here’s the tricky/infuriating/frustrating part. The metal frame is held to the outside door frame by ten plastic tabs that hook over the edge/perimeter of the metal frame to keep it attached to the outer door frame. Look carefully. There are three tabs on the top long edge, three on the bottom long edge, and two tabs on each short side. What you’ve got to try to do is GENTLY wedge "something" (I used a combination of large flat-blade screwdrivers, dowels, pliers handles, and wood blocks) to try to pull the "hook" part of these ten plastic tabs away from the metal frame towards the outer frame WITHOUT damaging the plastic outer frame. Also, be careful not to damage the latch that’s on your left. It’s not easy separating the tabs, and you’ll have a few frustrating attempts, but keep working around the perimeter of the metal frame, and you’ll eventually get enough wiggle to raise the metal frame. Yes, you’ll probably break a few of the plastic tabs, but that’s the price you pay for attempting this fix.
Once you have the inner door separated with its glass, set it aside.
Now you can see the handle’s lower attachment screw. YAAAY!! Go ahead and unscrew what’s left of the upper/lower handle and its posts, and throw that far, far away. When I installed the second replacement handle, (by count, the third handle since mfg), the mounting area on the outer door for the lower attachment screw was cracked. I tried to partially reinforce it with a metal washer under the attachment screw. (I figured there’s enough other metal in the inside door frame, the new metal washer won’t be arc’ing). Position the new/replacement handle correctly from the underside/outside, and then carefully snug the upper and lower handle screws. Put the door face down again on the counter, with the handle on the left side.
It probably couldn’t hurt to clean the inside glass of the door now that you can get to it, and then begin to put everything back together in reverse order:
GENTLY pop the inner door frame back in position, making sure the ten (or however many you have left after removing the inner door) tabs snap back over the perimeter of the inner metal frame. If the six screw holes line up okay, then put them back and gently tighten them once all six are in place.
GENTLY snap the dull/flat 2" inner frame back in place, making sure the two spring-loaded latches on the left side are aligned correctly.
Getting the door hinge pins back into their holes in the microwave hinges is a bit tricky, so you might want to have a helper support the door while you fuss with the alignment.
Re-attach the vent housing above the door opening using the two screws you removed earlier.
Plug the microwave back into its socket.
VOILA!!
Hope this has helped you. I’m not optimistic I won’t be having to replace my unit’s handle at least one more time before it’s time to update/upgrade to another range hood/microwave/convection oven. The new one needs to have better engineering of the door handle and latching mechanism, that’s for sure.
Cheers! 
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