To freeze your own coconut milk, use unsweetened canned full fat coconut milk or cream and fill an ice cube tray (those making extra small cubes are ideal.) Place in the freezer for at least a few hours.
To make this sorbet with a food processor instead of a juicer, let the frozen fruit and coconut milk cubes thaw for a bit longer (about 5 minutes), then add them all to your food processor at once and start blending (pulse first, then increase the speed little by little.) Blend until you get a smooth consistency. Then place the sorbet in the freezer to firm up a bit before serving.