You can walk from the house through Dimmuborgir, cycle or drive along the main road up to Hverfjall. Walk up the trail and round the crater. I prefer to go right when I come to the edge. From the car park round up and down again the ride takes about 2 hours. It is possible to go down into the crater if you are in good shape.
The pictures here are from a trip with my mother (87 years) in the summer of 2019