Recovering from a hosed up CUME install

[Pete Helgren <Pete@xxxxxxxxxx>]

I have a customer that, for the life of me, managed to install a CUME 
that just never seemed to fully apply (V5R4).  Over a year ago I 
invested 3 or 4 hours tracking which PTF(s) was(were)  a co-req or a 
pre-req and eventually was so confused by the circular logic (who's on 
first, what's on second...) that I have decided to start with a new CUME 
and apply it *clean*.  The question is, can I *undo* the previous CUME?  
I *think* the answer is yes, if I can slip the LIC and then load and 
apply the latest CUME.

Is that the best approach?  Or should I just I just plan to upgrade to 
6.1 and leave it at that? I'd rather not do the 6.1 upgrade at the 
moment so if there is a way to recover from a *bad* CUME install, I'd 
like to take that approach first.

Pete