OK for anyone else wondering I ended up following the guides at http://www.xpenology.nl/ to install a new ESXI VM. But I powered off my 4.3 VM and used it's vmdk as the second hard disk. Then I booted the VM, chose the 2nd option to install/upgrade. Synology Assistant came up saying it was Migratable. I went through the install process and it warned about how the disk was going to be wiped multiple times. I installed and it went fine. After I logged in a bunch of my shared folders were missing. Turns out the admin user lost all permissions. once I gave it read/write, it showed up in File Station. Now I'm on 5.0, woooo!