For the DPS 2015 workflow, the plug ins are included with the InDesign CC 2015 install. One option would be to uninstall InDesign and re-install it.
You may have downloaded and attempted to install the plug ins for InDesign CC 2014, that would result in an error if I recall correctly.
If you're running ID CC 2015, you should have an Overlay panel, and an export format "DPS Article" <-- that's what you need for the DPS 2015 workflow.
If you're running a different version of ID or using the older DPS 2014 workflow, let us know...
HTH;
Colin