Pour it into a gallon size freezer bag and remove as much air as possible.
Shake it up and place in the freezer.
Let it sit for 2 hours, checking it at 1 and 1.5 hours.
Break any pieces apart with your hands to avoid it forming a solid block.
Remove once desired consistency is reached.
Notes
Freezing time will vary depending on your freezer, just leave it in there until you are ready to eat it.I left our remaining amount in the freezer over night and it was still fine, it does start to get that "flat" taste when left in there for a while though.Note: Diet sodas freeze faster so keep a closer eye on them.