Before you attempt to change the language, identify the correct admin passcode (See How to identify the correct admin passcode below).
Change Language to English:
Enter *39#<admin-passcode>#2#
Change Language to Chinese:
Enter *39#<admin-passcode>#1#
How to identify the correct admin passcode:
When the lock is in an uninitialised state, use 123456 as the admin passcode. This is the state the lock is in when you receive the lock and after the lock has been reset.
When the lock is in an initialised state, find the system admin passcode under lock Settings -> Basics -> Admin Passcode. Please note the system admin passcode is not the same as the admin passcode you enter when setting up the lock.