Loosening the cam bolt without turning the chain was hard, so I used an air gun.
It was then tricky to re-loosen the crank bolt; eventually I got them both handtight so I could get both the crank bolt and cam bolt off.
The cam was tricky, I could only support the other end by reaching up through the bores and pushing up on the cam to enable it to clear the journals. I have very tiny scratches on one of the lobes, but they're too small to photograph and I can't feel them. I just need to worry about installing the new cam when the time comes.