Asus P1-PH1 - Manual (Page 36)

2-20 Chapter 2: Basic installation
2.10 Replacing the cover
After installing all system components and reconnecting all cables, replace
the system cover by following these instructions.
2. Position the cover at least two
inches from the front panel,
then align the cover hooks to
the chassis rail. 1. Replace the front panel cover
by fastening its hooks to the
chassis holes until they fit in
place.
4. Secure the system cover with
the screws you removed
earlier. 3. Push the system cover
toward the front panel until it
fits in place.