Done that a week ago. Royal PITA if you ask me.
First unscrew the antenna nut on your antenna.
Then you'd need to unplug you antenna motor plug going into the distribution box -
blue plug, behind the passengers kick panel I think.
It's damn tight in there, a little screwdriver actially helps disengage the latch which is on the bottom side of a plug.
Also disconnect the coaxial going to antenna - it's somewhere above the dist box under the dash, pretty tight too.
A pair of pliers does help.
Having done all that, you'd need to pull out the rubber plug in the side panel holding the cables. It's two piece - shell with motor wires and center plug with coaxial. You need to push out the center plug from inside, and then the outer rubber shell comes out easier. I learnt it the hard way trying to push the whole thing out.
Can take some photos of plugs taken out later if it helps