Chrome Bumper replacement on ruber bumper midget

Hello,

I am replacing my rubber bumper with a chrome bumper (mainly in hope to
increase air flow and reduce over heating, but also because it looks
nicer...)...

However, the mounts are completely different (I should have checked
before, isn't it... Ha the incontinence of youth!)...

Has anyone already done this conversion... Any tips or tricks?

Thanks, cyrille