Dell XPS 730 (Late 2008) - Manual (Page 93)

Replacing the Power Supply 91
9 Slide the power supply towards the front of the computer to free it from
the securing tabs on the computer chassis.
10 Slide the power supply toward the hard drive bay area, so that it will clear
the protruding lip of the chassis and lift the power supply from the
computer.
11 To replace the power supply, slide the new power supply into place,
ensuring that the tabs on the rear wall of the computer chassis latch into
place.
1 power supply screws (4)
1