Hello.  Had to install System Center Data Protection Manager 2012R2 today so took some screen shots along the way hopefully this can help someone walk through the process.
SQL2012R2_SP2 installed on server already.
SQL Service Account set up and granted full permissions.
SQL Server Service set to Log On As SQL Service Account.
SQL Server Agent Service set to Log On as SQL Service Account + Set to Automatic start.
SQL Server Reporting Services set to Log On as SQL Service Account.
SQL Reporting working fine.
Windows Single Instance Store Installed.
Visual C++ 2008 Redistributable
Windows Installer 4.5
…. see references at bottom of page for Technet Links.
Step one:  Launch the setup.exe and select Data Protection Manager

Step two:  Agree to the T’s & C’s…

Step three:  Next…

Step four:  Input the name of your SQLSERVERSQLINSTANCE (You’ll need to be logged on as an account that has permissions on the SQL server)

Step five:  Click on ‘Check and Install’

Step six: Input your product key…

Step seven: Chose your install folder and select to Use Microsoft Updates…

Step eight: Chose to be part of the Customer Experience Improvement Program…

Step nine: Confirm and set off the install.  Supposing you have got the pre-requisites in place you should experience no issues.

Here are some reference links for your attention:

Setup Prerequisites – https://technet.microsoft.com/en-us/library/hh758058.aspx
Preparing your environment for DPM 2012R2 –
Install DPM on a HyperV Server – https://technet.microsoft.com/en-US/library/dn440941.aspx

Thanks for reading, I hope this has been useful for you