Sometimes we want to download the operating system image file again and start from scratch when building a Vagrant VM.
If vagrant up does not load a new box even after a vagrant destroy of the existing VM, do the following.
Ensure the box_url variable in the Vagrantfile is set to the correct URL of the new box (config.vm.box_url).
View existing boxes to get the existing box name:
$ vagrant box list
myBox (virtualbox, 0)
Fully remove the box file:
$ vagrant box remove myBox
Now the box file listed in the Vagrantfile will be downloaded again when running vagrant up.