I would like to ask how have done it what I did, for making 2" holes for a clone system.
I was afraid the plastic in the lid would crack.
The best way to cut I found is to run the drill in reverse.
Tape the surface well and place a piece of soft wood lumber under it.
Apply light pressure when drilling and go slowly so the plastic doesn't melt.

What you want is a hole saw not just any hole saw one with fine teeth that would be used for drilling metal as opposed to wood

 

Dave,

Thanks!
Would you know the brand or part number by any chance?

You can get a set from harbor freight for 10 dollers. Comes with 1/2 to 3 1/2 inch. I use it to drill out a hole in a 5 gallon bucket with no problem. You can get a set anywhere but tgey can get pricey.

Not sure what kind of plastic but I second the $10 Harbor Freight one. I used it to cut holes in 2 gallon buckets and kitty litter buckets with no issue. The only problem is that they have been covered with some sort of grease so paper towels and lay newspaper down first.

Thanks for an advice!
That HF set, does it have more teeth like Dave mentioned?

Its between the two, more than one but maybe less than the other? Its 18pcs carbon steel hole set and on the box it says for wood and for plastic. I even have the receipt, it was 10.99 in November 2015.

I believe they have a cheaper version but it wasn't carbon steel and was 10 pcs.

Nice, Jen!
It looks closer to a dense version it seems.