For this fix you would need to find a specialized screwdriver that would fit into you oven door handle screws.
How to fix a broken oven door handle.
Remove the oven door.
Access the interior screws of the door handle.
Then partially close the door so you can lift it free of the hinge locks and slide it out towards yourself.
First open the door and snap open the hinges.
Gather your screws and get that new handle ready we have a screw with two spacer washers one locking washer and then a plastic washer which goes on the outside.
Support the door with a chair or your knee if necessary and then slide the hinge locks outward to unlock them.
If during your observation you notice that the screws are damaged you may need to buy new ones.
Take off the old handle and discard it if you don t need it to purchase a new one.
The door should come free without any friction.
This involves removing a lot of layers of parts.
Open the oven s door to expose its hinges.
Use an adjustable or socket wrench to remove the two nuts that hold the handle onto the oven door.
Lift the outer door towards you feed the screw and the two spacer washers and the locking washer through the screw hole before putting the plastic washer through it.
Have a damp cloth at hand if the screws are needed to be cleaned.
If it s a broken end just visible at the top of the above picture you can fabricate a patch using 6oz fiberglass and epoxy laminating resin.