If the counter does not bridge the opening at the rear wall, the rear filler kit that is provided with the slide-in range will be needed.
If the countertop depth is greater than 25 3/8" there will be a gap between the filler kit and the back wall.
If the countertop depth is less than 24 3/4", the control panel will not sit flush with the countertop.
Using a screwdriver, remove the 3 screws holding the rear top plate in place.

Attach the rear top plate and filler assembly as shown, using the 3 screws removed in step 1.

Rear filler