Hi, my name is ***** ***** I have been in the home improvement and repair field for 20 years. I will be very glad to help you today. First turn the power off. Remove the screws on the back at the top that hold the top in place. Now the top will be loose. Lift the top and place wood board across the appliance from front to back under the top for a work place.
Carefully lift the top and stand on it's edge on the board to access the bottom. Remove the two nuts holding the earth wires to the underside of the top. You may want to have a flat surface to place all the nuts and bolts on in the order that you remove them so that it will be easier to replace them later.
Now place a second piece of wood on the other side under the top from front to back and turn the top over and place it on the boards so that you may access the underneath.
Remove the fixing that holds the hotplate and disconnect the wires connected to the hotplate taking note of the wired connections by labeling them if they are not labeled well on the replacement. Be sure that the plates are on the wood so that they remain in place when disconnected. Remove the base cover plate but leave the insulation in place. Remove the plate and replace with new.