1. Create a directory for you local repository, e.g. /home/user/repo.
2. Move the RPMs into that directory.

3. Fix some ownership and filesystem permissions:

   # chown -R root.root /home/user/repo

4. Install the createrepo package if not installed yet, and run

   # createrepo /home/user/repo # chmod -R o-w+r /home/user/repo

5. Create a repository configuration file, e.g. /etc/yum.repos.d/myrepo.repo containing

   [local] name=My Awesome Repo baseurl=file:///home/user/repo enabled=1 gpgcheck=0

6. Install your package using

   # yum install packagename

The link you provided solved my case with just this one line: 

yum --nogpgcheck localinstall packagename.arch.rpm.