AT&T TL7000 User Manual page 12

Getting started
Handset lifter installation
Before installing the headset base:
Remove the rear bottom piece of the headset base by pushing it
away from the base (as shown in Figure 2).
Figure 2
Install the headset base as shown on pages 9-10.
After completing the headset base installation, slide the rear
bottom piece towards the base until it clicks into place (as shown
in Figure 3).
Figure 3
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