Or just stew them either on their own, or with some apples (and as much sugar as suits your preference), and then freeze them in plastic bags. This is what we do with the in-laws' glut of apples and pears that they get each year from the trees at the end of their garden.
Once defrosted, they're still lovely either with natural yoghurt, or as a crumble filling (although you may need to drain some of the juices off before putting into the crumble, which makes a lovely drink on its own
).