All RO or RO/DI units install the same way(s). You have several options. I assume your GE drinking water unit is hooked to the cold water supply line under the sink? You can use this same connection point for the RO/DI unit if its a standard 1/4" tube fitting as it appears to be.
Rather than explain it its much easier to understand using Air Water & Ice's installation instructions. Take a look at the Reefkeeper guide if you don't plan on having a pressure tank for drinking water, the Dual Home Reef or the Residential if you plan on using it for drinking water too and finally the Mighty Mite if you do not want to make it a permanent installation. Again any unit can be hooked up any of these ways but these instructions show good pictures which are easy to follow.
http://www.airwaterice.com/category/vv/