The Bulbs are very easy to install. I installed the bulbs and harness on my 2013 Chevy Camaro 2SS/RS. Turn the front wheels all the way to the left, on the passenger side wheel well, remove three T15 (Torx) screws on the inner fender liner and pull back the liner slightly.
For the bulb, just twist counterclockwise and pull, and then disconnect from the plug. Take note of the tab sizes and notches in the housing so that you line up the tabs on the new bulb the same way.
For the harness, un-plug the existing connector attached to the front of the car above the DRL by pulling back the gray retaining clip, and pressing down on the tab and pulling. Plug the new harness in, in between to the existing male and female plugs, re-install the retaining clip, install the three Torx screws to fasten the inner fender liner, and you done. There are some nice photos here on Modern Camaro dot com website that show you exactly where the harness is located.
Also, since you have the 2012 RS, at some point for this model year they changed the bulb number from a P13W to a PSX26W. so I would recommend pulling one of the existing bulbs to check number before buying your LEDs. My 2013 has a PSX26W.