As far as I know, logrotate is not a daemon that you restart but it's a process called from cron as a daily job. So there is nothing to restart. At the next scheduled run your config should be used when the logrotate process runs.
Of course if you want to run it to test your config then you can. It should be in /usr/sbin; so:
(if that's the location of your configuration file) should start it manually. And the next run will be triggered by the daily cron.