[CentOS] CentOS "upgrade" from fedora core ?

'Trying to figure out if it might be possible to set things up such that i 
could "upgrade" (rather than an "install") from a Fedora Core installation 
to CentOS.

'Had guessed that perhaps changing/faking the contents of 
/etc/redhat-release might do the job, but ... that didn't seem to go.

Anyone know how it might be accomplished?

Or perhaps this isn't a reasonable thing to do(?).


Thanks

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