Dell Precision 5860 Tower Service Manual page 116

Steps
1. Remove the six screws (M6x32) from the rail-kit.
2. Align the screw holes on the left rail-kit with the screw holes on the chassis.
3. Replace the six screws (M6x32) to secure the left rail-kit to the chassis
Next steps
1. Install the side cover.
2. Follow the procedure in After working inside your computer.
116 Removing and installing components