How do I cut this hole

[mr grimsdale]

...
I didn't think I'd get a holesaw that diameter. I don't really want to spend anything if I can as I only need 2 holes, so this will be my last resort option.....

Holesaws are made in sizes to loosely fit common sizes of tube, so there is nearly always one available.
Only prob in wood is that the teeth clog up very quickly - there's nowhere for the sawdust to go, so you have to keep pulling them out to brush the teeth.
I wondered about changing the teeth - perhaps a few big gullets to accommodate the dust, but I've never tried this.

 

[John. B]

If you look at 'My-Tool-Shed.co.uk' they have a Bahco 41 mm holesaw for £8.83
Might help?

John. B