Way to delete a plugin with server still running?

I can't delete it in FTP gives an error so I thought I seen a command on somewhere. Is this possible?

 

I believe the best way to do this is get Essentials. Then you can just delete the plugin from the plugins folder and do /reload, this will reload every plugin again and disables the plugins that are not in the plugins folder.

I think when you said that you think there was a command like this, you ment /plugin disable, which was previously in Essentials but doesn't seem to be anymore, or does exist but only does /reload. (Atleast for me)

 

you can /plugin disable with RestartNow, and you can do /reload without any plugins. Besides, essentials is bloated and such, if you don't already have it stay away from it :/