I use GIT to checkout U++ SVN tree, that is why I generated the patch also with GIT (git diff) and it should generate (as far as I can remember a unified diff). This can then normally used directly with 'patch' command like chickenk mentioned, the format should be understood by 'patch'.
I must admit I only generated the patch and did not check, so I will do this and come up with instructions later.
The patch should be applied to 'trunk' there is also 'newdraw' which I also tested.