Quoted from ST Manual
unlock.php & lock.php
Because secure.php disallow modification of files before ST update you have to unlock files before update and lock them back after updated is finished. Use unlock.php before update and lock.php after ST update (or you can again use secure.php). Files usage is very simple, there are no parameters just CD to st/admin directory and execute lock.php or unlock.php.This scripts could be executed as root or as user which was set in secure.php as files owner.
Command examples:
Code:
cd /home/domain.com/st/admin/
Code:
/bin/php unlock.php
Code:
cd /home/domain.com/st/admin/