Samsung Nexus S

Find "Location & security"

Press the menu icon.

Find "Location & security"

Press Settings.

Find "Location & security"

Press Location & security.

Choose option

Choose one of the following options:
Create phone lock code using a pattern, go to 2a.
Create phone lock code using a PIN, go to 2b.
Create phone lock code using a password, go to 2c.
Deactivate phone lock code, go to 2d.

2a - Create phone lock code using a pattern

Press Set up screen lock.

2a - Create phone lock code using a pattern

Press Pattern.
Press a point and drag it to connect at least four points to create a new phone lock code.

2a - Create phone lock code using a pattern

Press Continue.
Repeat the selected phone lock code to confirm.

2a - Create phone lock code using a pattern

Press Confirm.

2b - Create phone lock code using a PIN

Press Set up screen lock.

2b - Create phone lock code using a PIN

Press PIN.

2b - Create phone lock code using a PIN

Key in the required phone lock code and press Continue.

2b - Create phone lock code using a PIN

Key in the phone lock code again and press OK.

2c - Create phone lock code using a password

Press Set up screen lock.

2c - Create phone lock code using a password

Press Password.

2c - Create phone lock code using a password

Key in the required phone lock code and press Continue.

2c - Create phone lock code using a password

Key in the phone lock code again and press OK.

2d - Deactivate phone lock code

Press Change screen lock.
Key in the phone lock code.

2d - Deactivate phone lock code

Press None.

Exit

Press the Home key to return to standby mode.