Originally Posted by Mr. Spadoni

If it were me, I would take a metal tube, heat it and then push it through. The hole punches that Xiaoman have shown would work for this, as would metal tubing that you can buy in the US at the hardware store or hobby shops. I would NOT use anything that was not hot. There is too much material for the punch to cut cleanly and the material will distort under pressure.
A plus to the hot tube....you could try the tube on the inside of the hood. If it melts a clean cavity, then you are ready to try it for the hole. If not, you still have a good hood.
How successful you are will depend only the mix of rubber/plastic/ etc. that was used to make the hoods. It will likely smell very bad when you do it.
Buona fortuna