Want know how to open the top of range to clean?

This is not really meant to be done by user. If done incorrectly you could easily bend or break the gas lines to the top burners.

First you need to remove all the screws in the top burners and remove the burners. Then carefully twist out the ignitors. They do not necessarily have to be disconnected. Then remove all the knobs in front. and remove the manifold cover (that's the cover behind the knobs).

You will then be able to remove the screws that hold the top down and lift the top up high enough to clean under it. Lift this carefully though making sure that the gas lines do not bend when you do it.