Redmine

Hi!

I need help with Installing, Applying patchs for redmine.
I tried everything I found in the internet but I still can't use this patch: Extend Start/Due date to include time

So, can anyone give me a step by step tutorial to I use/apply/install this patch?
I need all steps even the simplest! How I said before I tried everything and still can't use.

I installed a redmine bitnami stack.

Here is my information about the version:

Environment:
Redmine version 2.5.1.stable
Ruby version 1.9.3-p231 (2012-05-25) [i386-mingw32]
Rails version 3.2.17
Environment production
Database adapter Mysql2

My redmine is on a Windows 7. (Not server edition)

Thanks in advance.