Epson 10020 - Manual (Page 107)

3. The top cover is secured by two screws on each side of the
computer. The two screws on the left side of the unit
are
covered by small plastic inserts, as shown below. Gently
remove the inserts with a small screwdriver; then remove
the screws on both sides of the computer. Put the screws
and inserts safely aside.
4. Tilt the cover up slightly from the back and pull it toward
you and away from the computer, as shown below. Set the
cover aside for now.
Installing Option Cards 4-3