Let's assume we use the default mysql command-line tool and MySQL as the backend database for Jira. If you are using a different database, you may need to change the following SQL statements accordingly:

1. Connect to the Jira database with a client tool by running the mysql -u jirauser -p command, where jirauser is the username used by Jira to access the Jira database.
2. You can find Jira's database details from the dbconfig.xml file located in JIRA_HOME.
3. Change to the Jira database by running the use jiradb command, where jiradb is the name of Jira's database.
4. Determine the groups that have the Jira System Administrator global permission with the following SQL statement:

select perm_parameter from 
schemepermissions where PERMISSION=44;

5. Find users that belong to the groups returned in the previous step by running the following SQL statement, where jira-administrators is a group returned from the previous step:

select child_name, directory_id
from cwd_membership where
parent_name='jira-administrators';

6. Reset the user's password in the database with the following SQL statement, where admin is a user returned in the previous step:

update cwd_user set
credential='uQieO/1CGMUIXXftw3ynrsaYLShI+
GTcPS4LdUGWbIusFvHPfUzD7
CZvms6yMMvA8I7FViHVEqr6Mj4pCLKAFQ==' where
user_name='admin';

7. Restart Jira to apply the change.