Added rudimentary instructions for generating a patch with git.

More advanced users will not even need to refer to this section.
diff --git a/ContributionReviews.wiki b/ContributionReviews.wiki
index 78385f3..dac2aa5 100644
--- a/ContributionReviews.wiki
+++ b/ContributionReviews.wiki
@@ -67,39 +67,24 @@
 that new functionality is introduced in one patch, 'enabled' in another one,
 and the old functionality removed in a third one.
 
-=== Patches (TODO: update this section to describe working with Git.) ===
+=== Patches ===
 
 The term "patches" is used to refer to relatively small changes to the
-code (and, yes, this definition is intentionally vague). Usually these are in the form of output from the `diff` command. It is easy to think of patches as changesets (commits), that are not part of repository history yet and can be passed around.
+code (and, yes, this definition is intentionally vague). Usually these are in the form of output from the `git diff` command.
 
-Patches should be sent for review to the [MailingListsGuidelines#Developer_list developer mailing list] and presented in the "unified `diff`" format, which is de-facto standard  for many tools and the output from the `hg diff` command for Mercurial (the same format as that produced by `diff -uNr`).
-Using Mercurial:
+Patches should be sent for review to the [MailingListsGuidelines#Developer_list developer mailing list] and presented in the "unified `diff`" format, which is de-facto standard  for many tools and the output from the `git diff` command (the same format as that produced by `diff -uNr`).
+Using Git:
 
 {{{
-cd ~/code/melange
-hg diff soc/models/new_model.py soc/views/deleted_model.py > my_change.diff
+git diff --no-prefix > your-patch-name.patch
 }}}
 
-or changes between two revisions
+The reviewer can then apply the patch using something like:
 
 {{{
-hg diff -r REV1:REV2 > my_change.diff
+patch -p0 < your-patch-name.patch
 }}}
 
-In this example, `new_model.py` would be a newly-added module, and
-`deleted_model.py` would be a just-deleted module.  The reviewer can
-then apply the patch using something like:
-
-{{{
-cd ~/code/melange
-hg import my_change.diff
-}}}
-
-The same root approach should be used with
-[http://codereviews.googleopensourceprograms.com/static/upload.py `upload.py`]
-to submit
-[ContributionReviews#Using_Rietveld_for_code_reviews Rietveld code reviews].
-
 ==== Patch emails ====
 
 Patch emails sent to the developer mailing list should begin with