Gateway 7250R System Manual page 59

3
Open the power supply cover by removing the two screws that secure it
in place, then swing the cover up.
4
Holding the sides of the power supply, push it out through the back panel
of the chassis.
5
Insert the new power supply through the back panel, making sure that
the connectors on the power supply seat firmly in the connectors on the
power distribution board.
6
Close the power supply cover and replace the screws you removed in
Step 3.
7
Close the case. (See "Closing the case" on page 20.)
8
Reconnect the power cord and all external peripherals, then turn on the
system.
52
Replacing and Adding Internal Devices