You can use the OS X combo update to bring your system up to date, and in the process, replace most of the key system software files with the most current versions included in the updater.
Ịnwere ike iji melite nghazi OS X iji weta usoro gị ruo ụbọchị, na n'usoro, dochie ọtụtụ n'ime usoro usoro usoro faịlụ na nsụgharị ndị dị ugbu a gụnyere updater.