Dell OptiPlex 7070 Ultra Setup And Specifications page 18

7. To release the stand cover, slide the release latch until you hear a click.
8. Slide and lift the cover to release it from the stand.
9. Align the vents on the device with the vents on the stand cover.
10. Lower the device in the stand until you hear a click.
18 Set up your OptiPlex 7070 Ultra