I am a plumber by trade so I was guessing my way through this. It took me a while to figure out that I had to drill out the screws that held the burners in place. The screws were so rusted that I couldn't tell that they were philips. Then I found that I needed to pull the stove out about 5" and put 2x4s under the feet so I could get the screws that hold the top down. I ruined the orfice holders trying to drill out the old screws.
I think my entire problem was caused by rust on the pan that the orfice holder is mounted to.
The stove is only 7 or 8 years old and this is the second repair I have had to do on it. I will never buy another JennAir.