Hi Fabricio, this should work.
then extract/install what you need from your Install Disc.
Pacifist should work, as long as any supporting libraries aren't missed. This article;
Which was in the user tip I published says how to restore from the original discs. If it fails to work, either the discs are damaged, the drive is damaged, or your machine needs a new PRAM battery.
You may also get better help from an Apple usergroup near you: