How can I access the mounting slots on the front ears of the 1780R/1781R rack mount case?

How can I access the mounting slots on the front ears of the 1780R/1781R rack mount case?

The front ears of the rack mount case are hidden behind the plastic covers which are part of the front panel of the instrument. To expose the front ears of the rack mount case, unscrew the four screws which are located on the back panel. There are two tabs on the top edge of the back panel and two tabs on the bottom edge. Unscrew the screws from these tabs and the instrument can be slid out of the case to expose the mounting slots in the front ears of the rack mount case. Once the rack mount case is installed in the rack, the instrument can be slid back into the case and the screws reinstalled in the tabs on the back of the case.