Yesterday I made three trips with my neighbour and my trailer, in which we transported all the bits of the stone that we could lift between us, without either of us hurting himself. The haul amounts to about one quarter or less of the total. All the remaining pieces are at least twice as big. My feeble rotary hammer made no impression on them; neither did my neighbour's sledgehammer (now broken) and pick (now bent). Next step is to hire or borrow some kind of breaker. Any ideas what level of power tool would be needed for the job?
Cheers Richard