Dell OptiPlex G1 - Manual (Page 40)

Optional Stand Removal (Low-Profile Chassis): Dell ™ OptiPlex ™ G1 Systems
To remove the optional stand, follow these steps:
1. Place the right side of the computer on a flat work surface.
2. Unscrew the optional-stand screw.
Use your fingers or a wide flat-blade screwdriver to unscrew the optional-stand screw.
3. Pull the stand away from the computer.
Disengage the three orientation nubs that position the stand and help secure it to the computer.