How do I update my previous reports with GeoIP?


I got stuck in this steps:

•run geoipUpdateRows.php script, from command line (or from the browser, but risk of timing out if your database is large)
•wait a few minutes until all your visitors data from the piwik_log_visit table have been processed.
•you now need to force Piwik to re-process all the past reports: drop all piwik_archive_* tables in your Piwik database. Piwik will automatically create them and re-process the reports.
•You should see Visitors countries and cities in your Visitors>Location report.

Question: How do I run a php file? is it possible in a browser? is there any other way to update the tables? please help