To move/rearrange the order of items in a list, go to the list's edit page and then drag your items to their desired places, or select the triangle on the right of each item to update its desired position with a new number in the list order.
Once you're done reordering your list, click "Save List Order" and the page will refresh with the new order.
When you update the order position of multiple items in your list, the order of the remaining items will automatically shift up/down in rank accordingly.
For example, if you have a list containing 10 items and want to move item #5 to the top of the list and item #3 to the bottom of the list, you will see the following changes:
Item #5 will move to the 1st position in the list, the previous 1st title will move to 2nd position, 2nd title will move to 3rd position, 4th title will remain in 4th position, 6th title will move to 5th, 7th will move to 6th, 8th will move to 7th, 9th will move to 8th, 10th will move to 9th, and item #3 will move to the bottom of the list.