Hi
With the mac screen-down on the table, slide it towards you so the the front lip (the bit the with speakers in) is over the edge of the table.
Now hold the mac steady with one hand and pull the the cover off with the other so that it pivots about the point where you are stuck.
Keep pivoting and pull hard. It will go twang and you may fall across the room but you won't break the lugs.
I've not seen a broken one - ever.