Solution 1:

My suggestion is to get a partition editor like gparted https://gparted.org/

  1. Put it on your datastore.
  2. Go into the properties of the VM and assign the ISO to the virtual CD/DVD
  3. Boot the VM, and press ESC and you should get a boot menu
  4. Select virtual CD/DVD
  5. Boot
  6. When loaded launch gparted, and you can then visually see what is going on.
  7. Delete,add, resize, or etc the necessary partitions.
  8. Commit your changes
  9. Wait for that to complete
  10. Reboot
  11. Don't press any key and it should boot normally.