Your hosting account's password can be quickly changed through your website's hPanel by accessing the Accounts → Change Password option:
NOTES:
Changing your hosting account's password will also change your default FTP account's password. If you want to change the password of addon domains or additional FTP accounts, you can do this from the FTP Accounts page
If you have SSH access, the SSH password is the same as the FTP password of your main domain. You can change this setting by creating an SSH-only password
If you want to change the password of the whole Hostinger account, you can do this at the Account Information page