Sony Xperia T

Find "Screen lock"

Press the menu icon.

Find "Screen lock"

Press Settings.

Find "Screen lock"

Press Security.

Find "Screen lock"

Press Screen lock.

Change phone lock code

Key in the phone lock code.

Change phone lock code

Press one of the following options:
Slide

Change phone lock code

Face Unlock

Change phone lock code

Pattern

Change phone lock code

PIN

Change phone lock code

Password.
Follow the instructions on the display to change the phone lock code.

Exit

Press the home icon to return to standby mode.