I installed the new cook top on Sunday. I helped my Dad install the old on 18 years ago so I felt reasonably comfortable installing this one. I read the installation instructions twice and dove in.
The first problem I had was when I plopped the new one into the hole.
It didn't fit.
The old one had rounded corners and so did the hole in the counter top. The new on was squared off.
My first thought was that my wife was going to kill me. I had measured side to side and front to back, but never checked the corners. (It's like the refrigerator and the doorway all over again!)
I remembered I purchased a jigsaw for $15 about 10 years ago at a yard sale, so I brought it in from the garage praying there were blades in the box. There were. I cut the corners square and it fell right in --almost.
Now the back edge was sticking up about 3/8 of an inch. It was resting on the junction box we screwed to the wall inside the cabinet.
There was a sheet rock screw holding the box to the wall and of course it was at an angle so I couldn't use my cordless drill. When I unscrewed it, and unscrewed it, and unscrewed it, I found out it was a 2 1/2 inch screw.
I moved the box down a bit and attached it with a 1 1/4 inch screw.
It works and life is good.