AT&T System 25 - Manual (Page 71)

INSTALLATION
Mount 858A or 2210A2 Adapters
To install these adapters, proceed as follows:
1. Using a wide blade screwdriver, pry off the upper adapter mounting
clip on the 617A Panel (Figure 2-18).
2. Fit the mounting clip on the top of the adapter.
3. Fit the adapter in the slot of the lower mounting clip.
4. Press the upper mounting clip back into the panel.
2-47