This should help :-
Removing software fixes
It is usually impossible to back out cume PTF packages. This is because there are almost always PTFs in the cume package that require Permanent application.
To back out a cume PTF package, restore your operating system and Licensed Program Products from backups made before the cume package was applied.
I’ve never heard of anyone backing out a cume package. I have, however, heard of individual PTFs from the package being backed out.