Redmine

Hi everyone,

I'm new on redmine.
How can I upgrade redmine from 2.4.3 to 2.5 or later.
The newest one is preferable.

In order to install redmine, I've utilized "sudo apt-get install redmine" with Ubuntu 14.04.
As a result, my redmine's version is 2.4.3 and it's not I wanted.
I'd like to use newer one, at least 2.5 to use Markdown.

There're much information over the web about upgrading,
but most of them assume that people install the first redmine from tar file, not with "apt-get".

What is the best way to upgrade redmine in the case redmine was installed with "apt-get" ?

Thanks in advance.