Multi-select problem: How does the next paragraph end?

How to change between tower and desktop orientations in a compaq evo tower
Remove the access panel.
On the back of the computer, use a screwdriver to remove the two screws that hold the access panel in place, then slide and lift it away from you.
Remove the front panel.

OPT:
(a). There are 3 panel behind the computer. Make sure you don't set the screws to the left or right of the header panel.;
(b). Press in on the two plastic tabs which are next to the underlying green arrows, then rotate it away from you and lift it out. Rotate the cd and floppy drives to the horizontal orientation.;
(c). Lay a large piece of its back on a solid table. Any materials that would not fit under the panel need to be removed.;
(d). The front panel is at the back of the computer, typically located on the front side of the desk. Locate it by looking at the side panel.;
(b).