How do edit column wise in an editor

As a programmer I google a lot for code snippets. A very prevalent problem is to copy code and to remove the line numbers. Its not always possible to copy code without the line numbers, so how do you go about deleting them?

For example code like this - http://www.java-examples.com/simple-java-treemap-example

Many sites either offer an option to copy just the code but some don't.

I have several solutions, what's your approach?