I have only installed the OEM Kia remote start on my 2014 Optima EX. Never had to deal with removing a box but removing the original harness plug on the drivers side up behind the parking brake was a nightmare. If my fingers were thin and long it would have been so much easier but none the less I was able to do it. Is this an aftermarket remote start? The Oem has you zip tie the control box up into the underside of the dashboard on the drivers side plus adding a wiring harness that is plug and play.