Lexus RX400h2006 Owner's Manual page 404

Push the number for the password and the "Enter" switch. The
"Select Restriction Level" screen will appear.
If you enter a wrong number, push the "Clear" switch to delete
the number.
You cannot change the setting without inputting the password.
When you forget or change the password, push the "Clear"
switch ten times to initialize the password.
To return to the "Setup Menu 1" screen, push the "Back" switch.
Push a parental level (1 — 8). The smaller the level number,
the stricter the age limit. Push the "Back" switch to return to the
"Setup Menu 1" screen.
AUDIO
377