carnt open .pkg

A few months ago my younger brother got his grubby mits on my macbook an managed to delete the utilities folder along with installer so I can no longer open .pkg files. is there a way to get installer back without reinstalling the os as thats not possible due to no cd drive(got squished whilst traveling so no longer works)

any help would be amazing as iv came up with nothing other than reinstalling and have not came up with a way to reinstall without cd.

thanks

You can get the Pacifist application for your version of the OS. Using it you can extract whatever subsystem you need from the install media.

Thanks mate it works great, been looking for something like that for ages and your the first to help