Mitel 3300 Technician's Handbook page 209

9. Remove the blanking plate from controller cover to expose the
APC-CX(i) II connectors.
10. Replace the controller cover.
To replace the APC-CX(i) II hard disk drive:
1. Power down the controller and remove the controller cover; see pages
47 and 129.
2. Remove the APC-CX(i) II Assembly by reversing the steps on page
195 of this document.
3. Turn the assembly over.
4. Remove the two retaining screws; see Figure 67.
Figure 66: Remove Blanking Plate
Install and Replace Units
199