- Log in to your Admin account run all three maintenance scripts at once.
- Macintosh HD > Applications > Utilities folder > Terminal
- Type the following, exactly as written: sudo periodic daily weekly monthly
- Press Return.
- Type your Admin password when prompted, then press Return.
- All three scripts will run in sequence with no visual feedback. You will know they are completed when the Terminal prompt returns.
This is paraphrased from this link: http://thexlab.com/faqs/maintscripts.html for more info and alternative options follow the aforementioned link.