Side skirts ...
Why are you wanting to replace them ?
Are they damaged or you just not like them ?
They are attached with a very strong double stick tape.
From what I remember it is very expensive.
And around the edges, on the rear section, it wraps around the metal and has pins or screws holding it tight.
I believe if you buy new panels it comes with double stick tape, but I might be wrong on this.
The tape the factory uses is industrial strength,
so when you remove the panels it can break the plastic off and or your paint.
I hav used raxor blades to cut the tape, then remove all the stuff ffrom the body.
Either way its not fun