U have to do it inside the trunk. Remove the inner fabric cover and the rear light unit to expose the antenna system. I remember there is a screw bolting the bottom of the antenna and another 1or 2 Bolts holding the upper parts, remove the power plug and the antenna cable connected withe the antenna unit. You can then slide the antenna out. I suggest u order the repair pack from the antenna manufacturer rather than buying the whole replacement unit from eBay. It's easy to replace gear once you receive the repair pack. I did that more than a year ago. It's easy and the antenna still works great! Let me try to find the repair pack info and get back to you. Good luck.