How to force Plesk admin user to change his password on first login?
This feature is not available in Plesk 12.5 . Currently it is under review, you can track its status on Plesk uservoice portal .
Plesk 12 or earlier :
# mysqldump -uadmin -p`cat /etc/psa/.psa.shadow` psa > psa_dump.sql
Login to Plesk database:
# mysql -uadmin -p`cat /etc/psa/.psa.shadow` psa
Run the following query to force password change:
mysql> update misc set val='false' where param='psa_configured';