How to edit .php and js files?

[mp3u]

Hi there,
Back with another newbie question. I have to alter .js and .php files on my server related to various elements of vBulletin. How do I do this? Do I have to download a special program to allow me to alter .js nd .php files? I can't seem to be able to open these files and on Rackspace you seem to have to download the file, tweak it then reupload it.
Any help with this basic yet crucial part of vb tweaking would be very appreciated.
Thanks

[Lynne]

You would just use a standard text editor. I use BBEdit, but that is Mac only. You may use Notepad if you are on a PC.

[mp3u]

So I just open the files with the text editor (or copy and paste the code) then make the changes? What about the file extension? If I save them won't they become .txt files? Sorry but I'm new to this side of things.

[Lynne]

They should keep the same file extension when you save them.

[mp3u]

Great, thanks for that Lynne - very helpful:)