Repairing Scout sill damage - removing underside sill potector?

On Friday I managed to put a big dent in the side of my 2010 octavia scout - on leaving a parking space I turned side-on into one of those bollards that car-park designers seem to love, which are just too short to see from the driving position. Thankfully I didn't drag the side of the car along the bollard so the dent is just in one place; the door is a mess but what concerns me more is the sill, which has been pushed in by about an inch or so where it met the bollard :-( 

Brilliant timing - I lost my job recently so theres no way I can afford to get it fixed professionally, even the normal running costs are a challenge. I guess they'd weld in a new sill section but thats beyond my abilities. All i can think to do is to try pulling out what I can and then building up the difference with P40 and P38. Its mostly covered by plastic trim afterwards so hopefully that under an aerosol spray job will look OK.

However the trim is also part of my problem: there is a black plastic stone chip protector running along the side/underneath of the sills all the way between the wheel arches (i.e. not just the top door-sill protector strips). At least it looks like plastic to me, but its fixed so firmly (even into the dent) that I guess it must be bonded on or something. Does anyone know how to get this off?

Many Thanks

Kev