Reload single plugin from hard disk

Hi, I have a plugin that updates itself but once it's updated the file the whole server needs to reload to read the new plugin file, is there a way to get it to reload that single plugin (in Java, not the command)?
Thanks.

 

Why would the whole server need to reload? Please explain

 

The plugin JAR file is forcefully replaced with a new version while the server is running, disabling and re enabling the the plugin does not reload the plugin file into the server but when you do a /reload the new plugin version is loaded.
If you do not do a /reload the new plugin will not be loaded and the server doesn't respond to any of the plugin's commands. If after that you reload or restart the server the commands will work again with the new plugin file.

 

This is something I'd like to understand how to do too. Bukkit still seems to keep disabled plugins in memory AND still tries to pass events to them :S