0. Resize virtualbox disk image
PS> C:\"Program Files"\Oracle\VirtualBox\VboxManage.exe modifyhd "E:\VirtualBox VMs\FreeBSD\FreeBSD.vdi" --resize 30000
1. boot the VM from the FreeBSD ISO
[Press F12 -> c]
2. Fix [CURRUPT]
# gpart recover ada0
3. Delete SWAP slide
# gpart delete -i 3 ada0
4. Resize ROOT
# gpart resize -i 2 -s 25G ada0
5. Create the new SWAP to the end
# gpart add -t freebsd-swap ada0
6. Grow the FS to the GPT size (25G)
# growfs /dev/da0p2
7. Profit! :-)