Steps
1. Used ROM Manager to create backup. ROM Manager froze. Rebooted and tried again (still froze).
2. Rebooted into CWM Recovery. Created "advanced backup" from recovery mode.
3. Reboot.
4. Tried using ROM Manager to create another backup. Successful this time.
5. Copied update-cm-9-20120519-NIGHTLY-galaxys2-signed.zip to internal storage.
6. Reboot into Recovery (long hold power button > Reboot > Recovery > OK)
7. Flashed update-cm-9-20120519-NIGHTLY-galaxys2-signed.zip
8. Wiped cache partition.
9. Wiped dalvik cache.
10. Reboot.
11. Done
Build number looks a little verbose
