How far have you got on this?
When you say you have removed all the screws which screws have you removed?
Ok to remove the hob top you need to remove the screws holding the side panels on at the back and bend them out .
Certian models have 2 screws either side holding the hob top down, Remove these.
Then remove the front countre sunk screws from the ceramic glass surround, Right and left hand side towards the front.
Remove the 2 screws securing the hob assembly to the controls mounting panel, right and left front and 2 screws securing the rear panel bracket left and right rear.
Then you can lift the hob top off and disconnect the wiring block on the left hand side.
The above is from the service manual so try that and see how it goes. But you will need to either fully remove the side panels or undo the screws at the back and bend the panels out.