In phpMyAdmin you can insert SQL code, which update labels. Inzert on tab SQL - "Run SQL query/queries on database ..."
If you use table prefix, you have to change names of tables "settings" and "settinggroups".
If you use table prefix, you have to change names of tables "settings" and "settinggroups".
UPDATE settings SET title="Send Notice To Post Author",
description="Send a a private message to the author of the edited post." WHERE name="modnotice_pm";
UPDATE settinggroups SET title="ModNotice Plus" WHERE name="modnotice";