how to patch diff into source code?

[Xah Lee]

could anyone help me with a diff/patch question?

i got the following patch:

--- lisp\textmodes\css-mode.el.orig     2008-03-01 20:28:16.000000000
+0100
+++ lisp\textmodes\css-mode.el  2009-01-19 09:14:55.138125000 +0100
@@ -369,5 +369,5 @@
                           (forward-comment (- (point-max)))
                           ;; FIXME: We should also skip punctuation.
-                          (not (memq (char-before) '(?\; ?\
{)))))))))))
+                          (not (or (bobp) (memq (char-before) '(?\;
?\{))))))))))))

 (defun css-forward-sexp (n)

how do i use diff (or other?) to merge it into source?
i've never used diff for patching.

i just found and used menu Tools‣Apply Patch, but then i got

patching file /Users/xah/web/emacs/css-mode.el
patch: **** malformed patch at line 8: ?\{))))))))))))

is it something i did wrong or the patch?

Thanks.

  Xah
∑ http://xahlee.org/

☄