You can manually apply the patch if you're careful.
I did it once before with a small patch, and I think it works like this....In the file marked by lines starting with +++, search for the unprefixed block of code after the line beginning with @@, and add the line(s) starting with + after it and before the next unprefixed block.
I could be wrong so
back up your original files and data before trying it.
Alternatively, this might work, I haven't tested it.
http://winmerge.org/