I failed to mention a step so I'm going to copy exactly what is in the service manual.

To remove the main top first remove the grates, burner caps and burners. Using a 1/4" socket wrench or nut driver remove the mounting screws at each burner orfice assembly.
Insert a putty knife or similar tool between the main top & manifold panel near the outside of the front corner. Push the putty knife toward the rear to release the maintop mounting clip. Repeat for both sides.
When the mounting clips are released the front edge of the cooktop can be lifted. Make sure the orifice assembly does not bind in the cooktop when raising the top to remove it from the range.
Lift the front of the cooktop and pull forawrd to disengage the back from the rear hinge bracket. The coktop can now be replaced by reversing the previous steps.