Siemens Gigaset M2 Professional Operating Manual page 115

Step by Step
> <
BASIC SERVICE
> <
PIN/COS
> <
CHANGE COS
Enabling the telephone again:
u Call the system menu.
[
Select and confirm the basic service.
[
Select the menu item and confirm.
[
Select the menu item and confirm.
o
Enter the PIN (code no.).
[
Press. If the PIN is correct, it will be confirmed with:
"carried out" on the display.
Telephone blocking
105