From the TiVo Central screen, choose Settings & Messages > Settings > Parental Controls. (Or, select the padlock icon from the large info banner.)
The padlock icon in the info banner shows the current state of Parental Controls.
Off No password or controls are set. The icon is dim and unlocked.
On Password and controls are set. The icon is bright and locked.
Temporarily Off Controls are set but turned off. The icon is bright and unlocked.
Once Parental Controls are on, you must enter your Parental Controls password to change any Parental Controls settings.