filezilla: recreating local files after loss of all data

[treasure]

My hard drive crashed a couple months ago. I lost ALL files, all data.
My website is still up and running, but there are some coding errors that I would dearly love to fix.
I've got filezilla, but none of the local site text survived the crash.
I have transferred one of the files in the remote site to the local site.

My problem: How do I access and correct the source code now that I have the file on the local site? I did manage to copy and paste the source code in the remote file to notepad on the local site. Then I saved it as html. But it doesn't work like html when I click it. I can't remember how I did this in the past. Help?

Thanks,
Tara