I like to use a milk frother to do this, but you can also mix well with a fork or small whisk.
Place the pint in the freezer and freeze for 24 hours so it is fully solid. Make sure you place it on a level surface in your freezer. I like to freeze without a lid as I find it reduces the hump that can form in the middle.
Remove the frozen pint from the freezer. If you have a 'hump' in the center, it's best to scrape most of it away with a spoon so it is mostly level.
Insert into the outer bowl, add the lid, and lock into position. Blend on 'Lite Ice-Cream'
Make a little well in the center, add the extra liquid (if using, see note), and re-spin on the same lite ice cream setting.
After the second spin, the frosty should be thick, creamy and ready to enjoy
