The seeds can be separated by placing berries in a blender with some water and pulsing them a few times, then rinse with water to remove bits of pulp and skins. The good seeds will sink.

Put them in lightly moistened sand, peat moss or a peat based potting mix in a plastic baggie in a refrigerator for about 3 months. Once they are stratified, you can sprinkle the seeds/peat mix on top of a container of soil. Make sure the seeds are near the surface, as they need light to germinate. Keep warm and moist, and they should germinate in a few weeks. Alternatively, you can plant them outside in a container this fall, and let them stratify naturally over winter.