Honda 2011 Civic Hybrid Owner's Manual page 242

Bluetooth HandsFreeLink
To change the PIN to a new number:
Select the phonebook you want. The
display will change as shown above.
Enter the current PIN for this
phonebook.
236
The display will change as shown
above.
Enter the new 4-digit PIN number.
You will be asked to re-enter the PIN
for verification.
To remove a PIN:
Select '' PIN number ,'' then select
'' Do not use PIN '' after you enter
the current PIN.