I can only speak for the mk3.
The door rubbing strips sit in a groove, in the groove are several holes where plastic clips are clipped into... once all clips are attached to the bodywork, the rubbing strip can be attached to the afore mentioned clips.
I assume the mk4 is similar, but perhaps without the groove.
The bumpers on the mk3 is totally different to the mk4 and so are the rubbing strips on it... but the mk4 ones looks identical to those running along the doors... so they are probably just using clips.
So if u wanna remove them... just "pop" the plastic off.. remove the clips and fill the holes, smooth it, prime it, paint it.
shouldnt be "too" hard .. or alternatively, u can appreciate ur rubbing strips are bodycoloured and smooth where as us mk1,2,3 owners have black rough plastic that needs smoothed, primed and painted b4 its bodycoloured! :'(