Usually it's not thespring but instead the "latch head", which has a little loop on the backside to hold the spring. The loop breaks off.
The latch head is the long plastic piece with two protruding hooks which activate the hidden door switches.
The door will need to be taken apart (but not removed from the oven!) to get to the latch head. See the attached example photo.
If you or a friend decide to look into it, we have critical safety and disassembly information at our site, linked here on Fixya:
http://tinyurl.com/yzjozk
You can order Sharp parts from Tritronics at
http://www.wehaveparts.com
We appreciate your thoughtful rating of our answer.