How to properly remove plugins?

I think I have some deleted plugins conflicting. How do I find out and how do I clean it up?

I found wp-clean-options plugin, but skeptical to trying it.

 

To remove plugins, first deactivate them and after that you can delete them. this is an easy way to get rid of some plugins.

 

you can remove the plugins with help of ftp....................................logoon with ftp.........and find plugins in a folder and then delete the unwanted plugins

 

But. I think it's more better first Deactivate plugin and then delete.

 

But that doesn't remove all teh crap from mySQL and inputs? Not all off the plugin will go away after removing it. If you added a lot of plugins and removed them, this will eventually load or overheat the processor?

 

yes it is better to deactivate and then delete

 

what should we do to remove all inputs about this.

 

Does anyone know who really created wordpress?