I think to rollback to a previous state, perform an rpm update with the --rollback option followed by a date/time specifier (the rollback is time-based because packages affect each other's configuration -- if you removed package a, then b, then c, and then rolled back only package a, the configuration could be broken). Some examples:

• rpm -Uhv --rollback '9:00 am'
• rpm -Uhv --rollback '4 hours ago'
• rpm -Uhv --rollback 'december 25'

Repackaged files are stored in /var/spool/repackage.