It's hard to help since you didn't mention what you tried and what went wrong.
I'll stare into my crystal ball and guess that the installer crashed with an error about trying to write to /dev/sdb, which is the NWSSTG device from which you booted.
I saw Paul talk someone through this on Freenode #fedora-ppc a few weeks ago; I'm not sure if it was in bugzilla. The workaround might have been to do a network install instead of letting that device be visible to the kernel at all.
If I guessed the wrong problem, use bugzilla