first Step for change Qnap ADMIN Password is press for 3 second the backside reset button.
If Administrator have disable it by setting on Qts interface follow the second Metod. It reset the admin password without lost any data on Qnap NAS.
SECOND METOD Step by Step:
Remove all disks
Power on without disks (keep removed)
wait for NAS boot-up, It take 3min
Hotplug all disks
Connect to NAS only by SSH using default user and password ( admin / admin )
Once connected at NAS by SSH run this command one at once:
mount /dev/md13 /mnt/ext
passwd ( at answer insert new password, repeat two time)
Wait For Complete NAS reboot and enter on it by WEBPAGE, change from it the admin password.
( THIS PASSWORD CHANGE IS VERY IMPORTANT, IF DON’T COMPLETE THIS STEP YOU HAVE TO REPEAT ALL FROM 1 POINT)