Epson EISA Desktop - Manual (Page 69)

Removing the Subassembly
You need to remove the subassembly if you are installing your
first hard disk drive, removing your only hard disk drive, or
installing or removing a hard disk drive that is mounted next to
the power supply.
Follow these steps:
1. Turn the computer so you are facing its front side.
2. Disconnect the power supply and drive cables from the backs
of all the drives installed in your computer. Note which
cables are connected to which drives so you can easily
reconnect them later.
3. Open the clasps holding the power supply and drive cables
to the side of the subassembly, as shown in the following
illustration. Then remove all the cables from the clasps.
4-6 Accessing Infernal Components