How to remove front bumper/grille/plastics

[fikse]

Have just got some extra horns that I want to mount on our '13 Berlingo. I want the horns to be placed so they are "hidden" from outside and weather, but still pointing forward with as little obsticles preventing noise to come out. The original horn is placed hidden, and sound is very low.
Best place I have found so far is in front of radiators, but I cannot figure out how to dismantle the plastics in a good way.
Does there exists any video or pictures describing this?