patching a file in Vista?

I usually patch Drupal files "by hand" becauase I haven't figured out how to do it "correctly" - but I want to learn.

I need to patch the video_youtube.module for authentication.

I tried using Eclipse, but when I tried to open the filename.patch file, I got a prompt from Vista to select a default program. When I selected Eclipse, it opened the file in a new instance of Eclipse, and same with the filename.module file. I tried renaming them with .txt extension, but patch doesn't work, I even changed the filename at the top of the patch to modulefilename.txt ---

I installed patch.exe (GnuWin32) - when I run it, I get a command window but no matter what I type into it, nothing happens. I also tried a Command window, cd to the patch.exe directory, but then when I type in "patch p0 < filename.patch" and Enter I get the error "file not found"

I placed the module and patch files in the bin directory with patch.exe

All the tutorials I found assume that I know how to use the app, but I am stalled at the starting line...