Here's the thing: the hole is as important part of this sculpture as anything else. You could say that the hole makes the sculpture 'work'.
You can't have form without space. Up to now the space has been all around the sculpture, which because of the change of plane has a definite front and back. The hole through the mass of wood connects the two surfaces and also introduces something new: a world of inner space, one that's active,
It's exciting thing to do! If you've ever knocked through a wall, from one room to the next, you know what I mean.
I run a pilot hole first. Normally I would be carving the surround wood into what will become the hole (the idea of 'form into space'), rather than work from the hole outwards. Here, however the pilot hole helps first with my direction and also with losing the waste.
Related video: Scrapers
Download: Thoughts about Hepworth and her sculpture; why I'm using hand tools and not power, and 'direct carving'. Also wood and tools etc.