[Newbies] Obsolete classes - I can find pointers to them, but how to get rid of them

[itsme213]

PointerFinder reveals numerous pointers to obsolete classes. All of them 
seem to originate from something that appears (in the PointerFinder window) 
as either:
    #Refactoring -> Refactoring class
or
    #EventManager -> EventManager class
with lots of additional info.

I have no idea how to even reach the handles that are holding onto these 
obsolete classes, them seem to be from Squeak code. Any pointers appreciated 
:-)

Sophie