Switch Git branch in development server

I have a Git repository structured as pic shows:

enter image description here

As you may see there is a development branch, that's the one I'm using at development server.

We are working (I and them) in new functionalities so developers works at unificacion branch and I continue developing at development, in order to not messing up things at "stable" development I have created merge-all which contains a merge between development and unificacion. Well, I need to swtich from development to merge-all in development server, how I do that?

I have this content at .git/config file but I'm not so sure to touch anything there.

[core]
        repositoryformatversion = 0
        filemode = true
        bare = false
        logallrefupdates = true
[remote "origin"]
        fetch = +refs/heads/*:refs/remotes/origin/*
        url = git@bitbucket.org:iosev/sis-php-source.git
[branch "master"]
        remote = origin
        merge = refs/heads/master

Can any give me some tips? I have read some docs (this, this and so on) but still not clear at all to me

Solution

Switching between branches use
    git checkout merge-all

Read below all you need to know about branching and merging
    http://git-scm.com/book/es/v2/Git-Branching-Basic-Branching-and-Merging