How to Apply patch

I would like to use the plugin In-Place-Editing in my app.But it requires a patch to be applied as given in "http://www.yjchen.url.tw/tips/in-place-editing-for-rails-20/" .I got the patch file and the plugin.I would like to know how can i apply patch???

The version at Commits · rails/in_place_editing · GitHub already has that patch.

Fred