Alright, I'm from the Netherlands so I have to translate the options in notepad.
- Paste the script in notepad
- Choose "save as"
- And if I'm right there are 2 options in a pulldown menu.
- save as textdocument (.txt)
- save as all files, I don't know of this is translated well

but that is the 2nd option under the first one.
If you save it like that, there is no extension behind the file, so you type .cs there. (In the save screen)
Good luck, if there are problems I here it from you.