Sometimes necessary so lets write this down so I won't forget next time.
This is easy for expanding. If you want to shrink the size it is going to be a bit harder, and I am not covering it in this note.
fdisk -l /dev/sda growpart --dry-run /dev/sda 2 # ^ device and then the partition to grow # The partition on the disk is now expanded. # now to expand the filesystem it contains df -h resize2fs /dev/sda2