Don't trust random sudo commands from strangers - you can literally delete everything (or anything else).
Now, apps are really folders full of stuff - and deleting a folder gets a flag after 'rm', in this case the 'recursive' flags, meaning it should dive into folders inside it). The next thing you need to know is that dragging a file to the terminal pastes the path into the terminal In order to run it as an admin you type sudo before it. The remove command is 'rm', so we'll use that.
Open the terminal (it's in your applications folder inside of a Utilities folder).
Here's the fastest way I know of to remove a stubborn file (assuming you can't get the normal trash method to work).